树剖杂题

P3128 [USACO15DEC] Max Flow P

树链剖分\(lca\)+树上差分

对于点权的差分就是\(s,t\)位置增加 \(lca(s,t)\&fa[lca(s,t)]\)位置减少

最后做一遍树上前缀和即可

错误:\(dfs2\)中\(tp\)写成了\(u\)

#include <bits/stdc++.h>
using namespace std;
#define mid (l+r>>1)
#define endl '\n'
#define inl inline
#define eb emplace_back
const int N = 3e5 + 5;
char buf[1<<24] , *p1 , *p2;
#define getchar() (p1==p2&&(p2=(p1=buf)+fread(buf,1,1<<24,stdin),p1==p2)?EOF:*p1++)
//#define getchar() cin.get();
int read()
{
	int x = 0 , f = 1;
	char ch = getchar();
	while ( !isdigit(ch) ) { if ( ch == '-' ) f = -1; ch = getchar(); }
	while ( isdigit(ch) ) { x = ( x << 1 ) + ( x << 3 ) + ( ch ^ 48 ); ch = getchar(); }
	return x * f ;
}

int n , m , dep[N] , sz[N] , fa[N] , son[N] , top[N] , a[N] , maxx;

vector<int> e[N];
inl void add ( int u , int v ) { e[u].eb(v); }

struct LCA 
{
	void dfs1 ( int u , int f )
	{
		dep[u] = dep[f] + 1 , fa[u] = f , sz[u] = 1;
		for ( auto v : e[u] )
			if ( v ^ f )
			{
				dfs1 ( v , u );
				sz[u] += sz[v];
				if ( sz[son[u]] < sz[v] ) son[u] = v;
			}
	}
	void dfs2 ( int u , int tp )
	{
		top[u] = tp;
		if ( son[u] ) dfs2 ( son[u] , tp );
		for ( auto v : e[u] ) if ( v ^ fa[u] && v ^ son[u] ) dfs2 ( v , v );
	}
	int lca ( int u , int v )
	{
		while ( top[u] != top[v] )
		{
			if ( dep[top[u]] < dep[top[v]] ) swap ( u , v );
			u = fa[top[u]];
		}
		if ( dep[u] < dep[v] ) swap ( u , v );
		return v;
	}
}L;

void dfs ( int u , int f )
{
	for ( auto v : e[u] ) if ( v ^ f ) dfs ( v , u ) , a[u] += a[v];
}

signed main ()
{
	ios::sync_with_stdio(false);
	cin.tie(nullptr) , cout.tie(nullptr);
	n = read() , m = read();
	for ( int i = 1 , u , v ; i < n ; i ++ ) u = read() , v = read() , add ( u , v ) , add ( v , u );
	L.dfs1 ( 1 , 0 ) , L.dfs2 ( 1 , 1 );
	for ( int i = 1 , x , y ; i <= m ; i ++ )
	{
		int s = read() , t = read();
		a[s] ++ , a[t] ++;
		a[L.lca(s,t)] -- , a[fa[L.lca(s,t)]] --;
	}
	dfs ( 1 , 0 );
	for ( int i = 1 ; i <= m ; i ++ ) maxx = max ( maxx , a[i] );
	cout << maxx << endl;
	return 0;
}

P3038 [USACO11DEC] Grass Planting G

边权转点权板子码力得到提升=v=

注意在最后查询的时候顶端的\(lca\)节点需要忽略具体操作即为\(query ( 1 , 1 , n , pos[v] + 1 , pos[u] );\)

线段树中也需要特判\(x>y\)的情况捏()

#include <bits/stdc++.h>
using namespace std;
#define mid (l+r>>1)
#define endl '\n'
#define inl inline
#define eb emplace_back
#define ls p<<1
#define rs p<<1|1
#define lson ls,l,mid
#define rson rs,mid+1,r
#define pii pair<int,int>
const int N = 3e5 + 5;
// char buf[1<<24] , *p1 , *p2;
// #define getchar() (p1==p2&&(p2=(p1=buf)+fread(buf,1,1<<24,stdin),p1==p2)?EOF:*p1++)
#define getchar() cin.get();
int read()
{
	int x = 0 , f = 1;
	char ch = getchar();
	while ( !isdigit(ch) ) { if ( ch == '-' ) f = -1; ch = getchar(); }
	while ( isdigit(ch) ) { x = ( x << 1 ) + ( x << 3 ) + ( ch ^ 48 ); ch = getchar(); }
	return x * f ;
}

int n , m , a[N];
int dep[N] , sz[N] , fa[N] , son[N];
int top[N] , timer , pos[N] , rev[N];

vector<int> e[N];
inl void add ( int u , int v ) { e[u].eb(v); }

struct LCA 
{
	void dfs1 ( int u , int f )
	{
		dep[u] = dep[f] + 1 , fa[u] = f , sz[u] = 1;
		for ( auto v : e[u] )
			if ( v ^ f )
			{
				dfs1 ( v , u ) , a[v] = 1 , sz[u] += sz[v];
				if ( sz[son[u]] < sz[v] ) son[u] = v;
			}
	}
	void dfs2 ( int u , int tp )
	{
		top[u] = tp , pos[u] = ++timer , rev[timer] = u;
		if ( son[u] ) dfs2 ( son[u] , tp );
		for ( auto v : e[u] ) if ( v ^ fa[u] && v ^ son[u] ) dfs2 ( v , v );
	}
}L;

struct seg
{
	struct node { int sum , add; } t[N<<2];
	inl void up ( int p ) { t[p].sum = t[ls].sum + t[rs].sum; } 
	inl void pushadd ( int p , int l , int r , int val ) { t[p].sum += ( r - l + 1 ) * val , t[p].add += val; }
	inl void down ( int p , int l , int r ) { if ( t[p].add ) pushadd ( lson , t[p].add ) , pushadd ( rson , t[p].add ) , t[p].add = 0; }
	void build ( int p , int l , int r )
	{
		if ( l == r ) return t[p].sum = a[rev[l]] , void();
		build ( lson ) , build ( rson ) , up(p);
	}
	void upd ( int p , int l , int r , int x , int y , int val )
	{
		if ( x > y ) return;
		if ( x <= l && r <= y ) return pushadd ( p , l , r , val ) , void();
		down ( p , l , r );
		if ( x <= mid ) upd ( lson , x , y , val );
		if ( mid + 1 <= y ) upd ( rson , x , y , val );
		up(p);
	}
	int query ( int p , int l , int r , int x , int y )
	{
		if ( x > y ) return 0;
		if ( x <= l && r <= y ) return t[p].sum;
		int res = 0; down ( p , l , r );
		if ( x <= mid ) res += query ( lson , x , y );
		else res += query ( rson , x , y );
		return res;
	}
	void updsum ( int u , int v )
	{
		while ( top[u] != top[v] )
		{
			if ( dep[top[u]] < dep[top[v]] ) swap ( u , v );
			upd ( 1 , 1 , n , pos[top[u]] , pos[u] , 1 );
			u = fa[top[u]];
		}
		if ( dep[u] < dep[v] ) swap ( u , v );
		upd ( 1 , 1 , n , pos[v] + 1 , pos[u] , 1 );
	}
	int querysum ( int u , int v )
	{
		int sum = 0;
		while ( top[u] != top[v] )
		{
			if ( dep[top[u]] < dep[top[v]] ) swap ( u , v );
			sum += query ( 1 , 1 , n , pos[top[u]] , pos[u] );
			u = fa[top[u]];
		}
		if ( dep[u] < dep[v] ) swap ( u , v );
		sum += query ( 1 , 1 , n , pos[v] + 1 , pos[u] );
		return sum;
	}
}T;

char op;
signed main ()
{
	ios::sync_with_stdio(false);
	cin.tie(0) , cout.tie(0);
	n = read() , m = read();
	for ( int i = 1 , u , v ; i < n ; i ++ ) u = read() , v = read() , add ( u , v ) , add ( v , u );
	L.dfs1 ( 1 , 0 ) , L.dfs2 ( 1 , 1 );
	for ( int i = 1 , u , v ; i <= m ; i ++ )
	{
		cin >> op , u = read() , v = read();
		if ( op == 'P' ) T.updsum ( u , v );
		else cout << T.querysum ( u , v ) << endl;
	}
	return 0;
}

P4427 [BJOI2018] 求和

对于\(k\)次方和维护一个\(pre[i][j]\)表示第\(i\)个节点到根节点的路径上的所有深度的\(j\)次方和因为\(k\)很小所以可以暴力用快速幂改

注意这里的\(dep[0]=-1\) 才能保证根节点的\(dep=0\)

减法有可能出现负数加一个\(mod\)即可

#include <bits/stdc++.h>
using namespace std;
#define mid (l+r>>1)
#define endl '\n'
#define inl inline
#define eb emplace_back
#define ls p<<1
#define rs p<<1|1
#define lson ls,l,mid
#define rson rs,mid+1,r
#define pii pair<int,int>
#define int long long 
const int N = 3e5 + 5;
const int mod = 998244353;
char buf[1<<24] , *p1 , *p2;
#define getchar() (p1==p2&&(p2=(p1=buf)+fread(buf,1,1<<24,stdin),p1==p2)?EOF:*p1++)
// #define getchar() cin.get();
int read()
{
	int x = 0 , f = 1;
	char ch = getchar();
	while ( !isdigit(ch) ) { if ( ch == '-' ) f = -1; ch = getchar(); }
	while ( isdigit(ch) ) { x = ( x << 1 ) + ( x << 3 ) + ( ch ^ 48 ); ch = getchar(); }
	return x * f ;
}

int n , m , dep[N] , fa[N] , sz[N] , son[N] , top[N] , pre[N][51];

vector<int> e[N];
inl void add ( int u , int v ) { e[u].eb(v); }

int ksm ( int base , int k )
{
	int res = 1;
	for ( ; k ; ( base *= base ) %= mod , k >>= 1 )
		if ( k & 1 ) ( res *= base ) %= mod;
	return res;
}

struct LCA 
{
	void dfs1 ( int u , int f )
	{
		dep[u] = dep[f] + 1 , fa[u] = f , sz[u] = 1;
		for ( int i = 0 ; i <= 50 ; i ++ ) ( pre[u][i] = pre[f][i] + ksm ( dep[u] , i ) ) %= mod;
		for ( auto v : e[u] )
			if ( v ^ f )
			{
				dfs1 ( v , u );
				sz[u] += sz[v];
				if ( sz[son[u]] < sz[v] ) son[u] = v;
			}
	}
	void dfs2 ( int u , int tp )
	{
		top[u] = tp;
		if ( son[u] ) dfs2 ( son[u] , tp );
		for ( auto v : e[u] ) if ( v ^ fa[u] && v ^ son[u] ) dfs2 ( v , v );
	}
	int lca ( int u , int v )
	{
		while ( top[u] != top[v] )
		{
			if ( dep[top[u]] < dep[top[v]] ) swap ( u , v );
			u = fa[top[u]];
		}
		if ( dep[u] < dep[v] ) swap ( u , v );
		return v;
	}
}L;


signed main ()
{
	ios::sync_with_stdio(false);
	cin.tie(0) , cout.tie(0);
	n = read();
	for ( int i = 1 , u , v ; i < n ; i ++ ) u = read() , v = read() , add ( u , v ) , add ( v , u );
	m = read() , dep[0] = -1;
	L.dfs1 ( 1 , 0 ) , L.dfs2 ( 1 , 1 );
	for ( int i = 1 , u , v , k ; i <= m ; i ++ )
	{
		u = read() , v = read() , k = read();
		cout << ( pre[u][k] + pre[v][k] - pre[L.lca(u,v)][k] + mod - pre[fa[L.lca(u,v)]][k] + mod ) % mod << endl;
	}
	return 0;
}

P6098 [USACO19FEB] Cow Land G

简单题树剖+单点修改区间查询线段树

#include <bits/stdc++.h>
using namespace std;
#define mid (l+r>>1)
#define endl '\n'
#define inl inline
#define eb emplace_back
#define ls p<<1
#define rs p<<1|1
#define lson ls,l,mid
#define rson rs,mid+1,r
#define pii pair<int,int>
const int N = 5e5 + 5;
char buf[1<<24] , *p1 , *p2;
#define getchar() (p1==p2&&(p2=(p1=buf)+fread(buf,1,1<<24,stdin),p1==p2)?EOF:*p1++)
// #define getchar() cin.get();
int read()
{
	int x = 0 , f = 1;
	char ch = getchar();
	while ( !isdigit(ch) ) { if ( ch == '-' ) f = -1; ch = getchar(); }
	while ( isdigit(ch) ) { x = ( x << 1 ) + ( x << 3 ) + ( ch ^ 48 ); ch = getchar(); }
	return x * f ;
}

int n , q , a[N];

int fa[N] , dep[N] , sz[N] , son[N];
int timer , pos[N] , top[N] , rev[N];

vector<int> e[N];
inl void add ( int u , int v ) { e[u].eb(v); }

struct LCA
{
	void dfs1 ( int u , int f )
	{
		fa[u] = f , sz[u] = 1 , dep[u] = dep[f] + 1;
		for ( auto v : e[u] )
			if ( v ^ f )
			{
				dfs1 ( v , u );
				sz[u] += sz[v];
				if ( sz[son[u]] < sz[v] ) son[u] = v;
			}
	}
	void dfs2 ( int u , int tp )
	{
		top[u] = tp , pos[u] = ++timer , rev[timer] = u;
		if ( son[u] ) dfs2 ( son[u] , tp );
		for ( auto v : e[u] ) if ( v ^ fa[u] && v ^ son[u] ) dfs2 ( v , v );
	}
}L;

struct Tree
{
	struct node { int sum; } t[N<<2];
	inl void up ( int p ) { t[p].sum = t[ls].sum ^ t[rs].sum; }
	void build ( int p , int l , int r )
	{
		if ( l == r ) return t[p].sum = a[rev[l]] , void();
		build ( lson ) , build ( rson ) , up(p);
	}
	void upd ( int p , int l , int r , int x , int val )
	{
		if ( l == r ) return t[p].sum = val , void();
		if ( x <= mid ) upd ( lson , x , val );
		else upd ( rson , x , val );
		up(p);
	}
	int query ( int p , int l , int r , int x , int y )
	{
		if ( x > y ) return 0;
		if ( x <= l && r <= y ) return t[p].sum;
		int res = 0;
		if ( x <= mid ) res ^= query ( lson , x , y );
		if ( mid + 1 <= y ) res ^= query ( rson , x , y );
		return res;
	}
	int querysum ( int u , int v )
	{
		int res = 0;
		while ( top[u] != top[v] )
		{
			if ( dep[top[u]] < dep[top[v]] ) swap ( u , v );
			res ^= query ( 1 , 1 , n , pos[top[u]] , pos[u] );
			u = fa[top[u]];
		}
		if ( dep[u] < dep[v] ) swap ( u , v );
		res ^= query ( 1 , 1 , n , pos[v] , pos[u] );
		return res;
	}
}T;

signed main ()
{
	ios::sync_with_stdio(false);
	cin.tie(0) , cout.tie(0);
	n = read() , q = read();
	for ( int i = 1 ; i <= n ; i ++ ) a[i] = read();
	for ( int i = 1 , u , v ; i < n ; i ++ ) u = read() , v = read() , add ( u , v ) , add ( v , u );
	L.dfs1 ( 1 , 0 ) , L.dfs2 ( 1 , 1 ) , T.build ( 1 , 1 , n );
	for ( int i = 1 ; i <= q ; i ++ )
	{
		int op = read() , u = read() , v = read();
		if ( op == 1 ) T.upd ( 1 , 1 , n , pos[u] , v );
		else cout << T.querysum ( u , v ) << endl;
	}
	return 0;
}

P4315 月下“毛景树”

码量 \(max\) 调试 \(max\) 但还是很板子() 注意线段树下传标记的时候要先下传\(cov\)再下传\(add\)

#include <bits/stdc++.h>
using namespace std;
#define mid (l+r>>1)
#define endl '\n'
#define inl inline
#define eb emplace_back
#define ls p<<1
#define rs p<<1|1
#define lson ls,l,mid
#define rson rs,mid+1,r
#define pii pair<int,int>
#define int long long 
const int N = 1e5 + 5;
// char buf[1<<24] , *p1 , *p2;
// #define getchar() (p1==p2&&(p2=(p1=buf)+fread(buf,1,1<<24,stdin),p1==p2)?EOF:*p1++)
#define getchar() cin.get();
int read()
{
	int x = 0 , f = 1;
	char ch = getchar();
	while ( !isdigit(ch) ) { if ( ch == '-' ) f = -1; ch = getchar(); }
	while ( isdigit(ch) ) { x = ( x << 1 ) + ( x << 3 ) + ( ch ^ 48 ); ch = getchar(); }
	return x * f ;
}

int n , a[N] , x[N] , y[N] , w[N];

vector<pii> e[N];
inl void add ( int u , int v , int w ) { e[u].eb(v,w); }

int dep[N] , sz[N] , son[N] , fa[N];
int pos[N] , timer , top[N] , rev[N];

struct LCA
{
	void dfs1 ( int u , int f )
	{
		dep[u] = dep[f] + 1 , fa[u] = f , sz[u] = 1;
		for ( auto [v,w] : e[u] )
			if ( v ^ f )
			{
				dfs1 ( v , u );
				sz[u] += sz[v] , a[v] = w;
				if ( sz[son[u]] < sz[v] ) son[u] = v;
			}
	}
	void dfs2 ( int u , int tp )
	{
		top[u] = tp , pos[u] = ++timer , rev[timer] = u;
		if ( son[u] ) dfs2 ( son[u] , tp );
		for ( auto [v,w] : e[u] ) if ( v ^ fa[u] && v ^ son[u] ) dfs2 ( v , v );
	}
}L;

struct segtree
{
	struct node { int maxx , cov , add; } t[N<<2];
	inl void up ( int p ) { t[p].maxx = max ( t[ls].maxx , t[rs].maxx ); }
	inl void pushcov ( int p , int val ) { t[p].maxx = val , t[p].cov = val , t[p].add = 0; }
	inl void pushadd ( int p , int val ) { t[p].maxx += val , t[p].add += val; }
	inl void down ( int p )
	{
		if ( t[p].cov != -1 ) pushcov ( ls , t[p].cov ) , pushcov ( rs , t[p].cov ) , t[p].cov = -1;
		if ( t[p].add ) pushadd ( ls , t[p].add ) , pushadd ( rs , t[p].add ) , t[p].add = 0; 
	}
	void build ( int p , int l , int r )
	{
		t[p].cov = -1;
		if ( l == r ) return t[p].maxx = a[rev[l]] , void();
		build ( lson ) , build ( rson ) , up(p);
	}
	void upd ( int p , int l , int r , int x , int val )
	{
		if ( l == r ) return t[p].maxx = val , void();
		down(p);
		if ( x <= mid ) upd ( lson , x , val );
		else upd ( rson , x , val );
		up(p);
	}
	
	void cover ( int p , int l , int r , int x , int y , int val )
	{
		if ( x <= l && r <= y ) return pushcov ( p , val ) , void();
		down(p);
		if ( x <= mid ) cover ( lson , x , y , val );
		if ( mid + 1 <= y ) cover ( rson , x , y , val );
		up(p);
	}
	void coversum ( int u , int v , int val )
	{
		while ( top[u] != top[v] )
		{
			if ( dep[top[u]] < dep[top[v]] ) swap ( u , v );
			cover ( 1 , 1 , n , pos[top[u]] , pos[u] , val );
			u = fa[top[u]];
		}
		if ( dep[u] < dep[v] ) swap ( u , v );
		cover ( 1 , 1 , n , pos[v] + 1 , pos[u] , val );
	}

	void add ( int p , int l , int r , int x , int y , int val )
	{
		if ( x <= l && r <= y ) return pushadd ( p , val ) , void();
		down(p);
		if ( x <= mid ) add ( lson , x , y , val );
		if ( mid + 1 <= y ) add ( rson , x , y , val );
		up(p);
	}
	void addsum ( int u , int v , int val )
	{
		while ( top[u] != top[v] )
		{
			if ( dep[top[u]] < dep[top[v]] ) swap ( u , v );
			add ( 1 , 1 , n , pos[top[u]] , pos[u] , val );
			u = fa[top[u]];
		}
		if ( dep[u] < dep[v] ) swap ( u , v );
		add ( 1 , 1 , n , pos[v] + 1 , pos[u] , val );
	}

	int query ( int p , int l , int r , int x , int y )
	{
		if ( x > y ) return 0;
		if ( x <= l && r <= y ) return t[p].maxx;
		int res = 0; down(p);
		if ( x <= mid ) res = max ( res , query ( lson , x , y ) );
		if ( mid + 1 <= y ) res = max ( res , query ( rson , x , y ) );
		return res;
	}
	int maxx ( int u , int v )
	{
		int res = 0;
		while ( top[u] != top[v] )
		{
			if ( dep[top[u]] < dep[top[v]] ) swap ( u , v );
			res = max ( res , query ( 1 , 1 , n , pos[top[u]] , pos[u] ) );
			u = fa[top[u]];
		}
		if ( dep[u] < dep[v] ) swap ( u , v );
		res = max ( res , query ( 1 , 1 , n , pos[v] + 1 , pos[u] ) );
		return res; 
	}
}T;

string s;
signed main ()
{
	ios::sync_with_stdio(false);
	cin.tie(0) , cout.tie(0);
	n = read();
	for ( int i = 1 ; i < n ; i ++ ) x[i] = read() , y[i] = read() , w[i] = read() , add ( x[i] , y[i] , w[i] ) , add ( y[i] , x[i] , w[i] );
	L.dfs1 ( 1 , 0 ) , L.dfs2 ( 1 , 1 ) , T.build ( 1 , 1 , n );
	while(1)
	{
		cin >> s;
		if ( s == "Stop" ) break;
		int u = read() , v = read();
		switch ( s[1] )
		{
			case 'a' : cout << T.maxx ( u , v ) << endl; break;
			case 'h' : T.upd ( 1 , 1 , n , pos[max(x[u],y[u])] , v ); break;
			case 'd' : T.addsum ( u , v , read() ); break;
			case 'o' : T.coversum ( u , v , read() ); break;
		}
	}
	return 0;
}

P4092 [HEOI2016/TJOI2016] 树

非常板的树剖但预处理\(dep\)不当导致调试半小时

相当于是每次将某一个点打上标记(也就是将这个点的\(maxx\)改为深度) 那么对于一次询问询问的是这条链上的最大深度如果是\(0\)就说明没有标记点继续向上跳否则直接返回最大深度对应的节点编号

#include <bits/stdc++.h>
using namespace std;
#define mid (l+r>>1)
#define endl '\n'
#define inl inline
#define eb emplace_back
#define ls p<<1
#define rs p<<1|1
#define lson ls,l,mid
#define rson rs,mid+1,r
const int N = 1e5 + 5;
// char buf[1<<24] , *p1 , *p2;
// #define getchar() (p1==p2&&(p2=(p1=buf)+fread(buf,1,1<<24,stdin),p1==p2)?EOF:*p1++)
#define getchar() cin.get();
int read()
{
	int x = 0 , f = 1;
	char ch = getchar();
	while ( !isdigit(ch) ) { if ( ch == '-' ) f = -1; ch = getchar(); }
	while ( isdigit(ch) ) { x = ( x << 1 ) + ( x << 3 ) + ( ch ^ 48 ); ch = getchar(); }
	return x * f ;
}

int n , m , a[N];

vector<int> e[N];
inl void add ( int u , int v ) { e[u].eb(v); }

int dep[N] , fa[N] , sz[N] , son[N];
int top[N] , timer , pos[N] , rev[N];

struct LCA 
{
	void dfs1 ( int u , int f )
	{
		dep[u] = dep[fa[u] = f] + 1 , sz[u] = 1;
		for ( auto v : e[u] )
			if ( v ^ f )
			{
				dfs1 ( v , u );
				sz[u] += sz[v];
				if ( sz[son[u]] < sz[v] ) son[u] = v;
			}
	}		
	void dfs2 ( int u , int tp )
	{
		top[u] = tp , pos[u] = ++timer , rev[timer] = u;
		if ( son[u] ) dfs2 ( son[u] , tp );
		for ( auto v : e[u] ) if ( v ^ fa[u] && v ^ son[u] ) dfs2 ( v , v );
	}
}L;

struct tree
{
	struct node { int maxx = 0; } t[N<<2];
	inl void up ( int p ) { t[p].maxx = max ( t[ls].maxx , t[rs].maxx ); }
	void upd ( int p , int l , int r , int x )
	{
		if ( l == r ) return t[p].maxx = x , void();
		if ( x <= mid ) upd ( lson , x );
		else upd ( rson , x );
		up(p);
	}

	int query ( int p , int l , int r , int x , int y )
	{
		if ( x <= l && r <= y ) return t[p].maxx;
		int maxx = 0;
		if ( x <= mid ) maxx = max ( maxx , query ( lson , x , y ) );
		if ( mid + 1 <= y ) maxx = max ( maxx , query ( rson , x , y ) );
		return maxx;
	}
	int querymark ( int u , int v ) 
	{
		while ( top[u] != top[v] )
		{
			if ( dep[top[u]] < dep[top[v]] ) swap ( u , v );
			int tmp = query ( 1 , 1 , n , pos[top[u]] , pos[u] );
			if ( tmp ) return rev[tmp];
			u = fa[top[u]];
		}
		// cout << u << v << endl;
		if ( dep[u] < dep[v] ) swap ( u , v );
		// cout << "st" << endl;
		// cout << v << ' ' << u << endl;
		// cout << pos[v] << ' ' << pos[u] << endl;
		// cout << "ed" << endl;
		return rev[query ( 1 , 1 , n , pos[v] , pos[u] )];
	}
}T;

char ch;
signed main ()
{
	ios::sync_with_stdio(false);
	cin.tie(0) , cout.tie(0);
	n = read() , m = read();
	for ( int i = 1 , u , v ; i < n ; i ++ ) u = read() , v = read() , add ( u , v ) , add ( v , u );
	L.dfs1 ( 1 , 0 ) , L.dfs2 ( 1 , 1 );
	T.upd ( 1 , 1 , n , pos[1] );
	while ( m -- )
	{
		cin >> ch;
		int u = read();
		if ( ch == 'C' ) T.upd ( 1 , 1 , n , pos[u] );
		else cout << T.querymark ( 1 , u ) << endl;
	}
	return 0;
}

P3833 [SHOI2012] 魔法树

很板的题相当于是树链剖分+区间修改区间查询线段树

#include <bits/stdc++.h>
using namespace std;
#define mid (l+r>>1)
#define endl '\n'
#define inl inline
#define eb emplace_back
#define ls p<<1
#define rs p<<1|1
#define lson ls,l,mid
#define rson rs,mid+1,r
#define int long long
const int N = 1e5 + 5;

// char buf[1<<24] , *p1 , *p2;
// #define getchar() (p1==p2&&(p2=(p1=buf)+fread(buf,1,1<<24,stdin),p1==p2)?EOF:*p1++)
#define getchar() cin.get();
int read()
{
	int x = 0 , f = 1;
	char ch = getchar();
	while ( !isdigit(ch) ) { if ( ch == '-' ) f = -1; ch = getchar(); }
	while ( isdigit(ch) ) { x = ( x << 1 ) + ( x << 3 ) + ( ch ^ 48 ); ch = getchar(); }
	return x * f ;
}

int n , m , a[N];

vector<int> e[N];
inl void add ( int u , int v ) { e[u].eb(v); }

int dep[N] , fa[N] , sz[N] , son[N];
int top[N] , timer , pos[N] , rev[N];

struct LCA 
{
	void dfs1 ( int u , int f )
	{
		dep[u] = dep[fa[u] = f] + 1 , sz[u] = 1;
		for ( auto v : e[u] )
			if ( v ^ f )
			{
				dfs1 ( v , u );
				sz[u] += sz[v];
				if ( sz[son[u]] < sz[v] ) son[u] = v;
			}
	}		
	void dfs2 ( int u , int tp )
	{
		top[u] = tp , pos[u] = ++timer , rev[timer] = u;
		if ( son[u] ) dfs2 ( son[u] , tp );
		for ( auto v : e[u] ) if ( v ^ fa[u] && v ^ son[u] ) dfs2 ( v , v );
	}
}L;

struct tree
{
	struct node { int sum , add; } t[N<<2];
	inl void up ( int p ) { t[p].sum = t[ls].sum + t[rs].sum; }
	inl void pushadd ( int p , int l , int r , int val ) { t[p].add += val , t[p].sum += ( r - l + 1 ) * val; }
	inl void down ( int p , int l , int r ) { if ( t[p].add ) pushadd ( lson , t[p].add ) , pushadd ( rson , t[p].add ) , t[p].add = 0; }
	void upd ( int p , int l , int r , int x , int y , int val )
	{
		if ( x <= l && r <= y ) return pushadd ( p , l , r , val ) , void();
		down(p,l,r);
		if ( x <= mid ) upd ( lson , x , y , val );
		if ( mid + 1 <= y ) upd ( rson , x , y , val );
		up(p);
	}
	int query ( int p , int l , int r , int x , int y )
	{
		if ( x <= l && r <= y ) return t[p].sum;
		int sum = 0; down(p,l,r);
		if ( x <= mid ) sum += query ( lson , x , y );
		if ( mid + 1 <= y ) sum += query ( rson , x , y );
		return sum;
	}
	void updsum ( int u , int v , int w )
	{
		while ( top[u] != top[v] )
		{
			if ( dep[top[u]] < dep[top[v]] ) swap ( u , v );
			upd ( 1 , 1 , n , pos[top[u]] , pos[u] , w );
			u = fa[top[u]];
		}
		if ( dep[u] < dep[v] ) swap ( u , v );
		upd ( 1 , 1 , n , pos[v] , pos[u] , w );
	}
}T;

char ch;
signed main ()
{
	ios::sync_with_stdio(false);
	cin.tie(0) , cout.tie(0);
	n = read();
	for ( int i = 1 , u , v ; i < n ; i ++ ) u = read() + 1 , v = read() + 1 , add ( u , v ) , add ( v , u );
	L.dfs1 ( 1 , 0 ) , L.dfs2 ( 1 , 1 );
	m = read();
	for ( int i = 1 , u , v , w ; i <= m ; i ++ )
	{
		cin >> ch;
		if ( ch == 'A' ) u = read() + 1 , v = read() + 1 , w = read() , T.updsum ( u , v , w );
		else u = read() + 1 , cout << T.query ( 1 , 1 , n , pos[u] , pos[u] + sz[u] - 1 ) << endl;
	}
	return 0;
}

P1505 [国家集训队] 旅游

码量 \(max\) 但实际上并不难()

#include <bits/stdc++.h>
using namespace std;
#define mid (l+r>>1)
#define endl '\n'
#define inl inline
#define eb emplace_back
#define ls p<<1
#define rs p<<1|1
#define lson ls,l,mid
#define rson rs,mid+1,r
#define pii pair<int,int>
const int N = 2e5 + 5;
const int inf = 0x3f3f3f3f;

// char buf[1<<24] , *p1 , *p2;
// #define getchar() (p1==p2&&(p2=(p1=buf)+fread(buf,1,1<<24,stdin),p1==p2)?EOF:*p1++)
#define getchar() cin.get();
int read()
{
	int x = 0 , f = 1;
	char ch = getchar();
	while ( !isdigit(ch) ) { if ( ch == '-' ) f = -1; ch = getchar(); }
	while ( isdigit(ch) ) { x = ( x << 1 ) + ( x << 3 ) + ( ch ^ 48 ); ch = getchar(); }
	return x * f ;
}

int n , m , a[N] , u[N] , v[N] , w[N];

vector<pii> e[N];
inl void add ( int u , int v , int w ) { e[u].eb(v,w); }

int dep[N] , fa[N] , sz[N] , son[N];
int top[N] , timer , pos[N] , rev[N];

struct LCA 
{
	void dfs1 ( int u , int f )
	{
		dep[u] = dep[fa[u] = f] + 1 , sz[u] = 1;
		for ( auto [v,w] : e[u] )
			if ( v ^ f )
			{
				dfs1 ( v , u ) , a[v] = w , sz[u] += sz[v];
				if ( sz[son[u]] < sz[v] ) son[u] = v;
			}
	}		
	void dfs2 ( int u , int tp )
	{
		top[u] = tp , pos[u] = ++timer , rev[timer] = u;
		if ( son[u] ) dfs2 ( son[u] , tp );
		for ( auto [v,w] : e[u] ) if ( v ^ fa[u] && v ^ son[u] ) dfs2 ( v , v );
	}
}L;

struct tree
{
	struct node { int sum , maxx , minn , rev; } t[N<<2];
	inl void up ( int p ) { t[p].sum = t[ls].sum + t[rs].sum , t[p].minn = min ( t[ls].minn , t[rs].minn ) , t[p].maxx = max ( t[ls].maxx , t[rs].maxx ); }
	inl void pushrev ( int p ) { t[p].rev ^= 1 , t[p].sum = -t[p].sum , t[p].maxx = -t[p].maxx , t[p].minn = -t[p].minn , swap ( t[p].maxx , t[p].minn ); }
	inl void down ( int p ) { if ( t[p].rev ) pushrev(ls) , pushrev(rs) , t[p].rev ^= 1; }
	void build ( int p , int l , int r )
	{
		if ( l == r ) return t[p].maxx = t[p].minn = t[p].sum = a[rev[l]] , void();
		build(lson) , build(rson) , up(p);
	}
	void upd ( int p , int l , int r , int x , int val )
	{
		if ( l == r ) return t[p].maxx = t[p].minn = t[p].sum = val , void();
		down(p);
		if ( x <= mid ) upd ( lson , x , val );
		else upd ( rson , x , val );
		up(p);
	}
	
	void updrev ( int p , int l , int r , int x , int y )
	{
		if ( x <= l && r <= y ) return pushrev(p) , void();
		down(p);
		if ( x <= mid ) updrev ( lson , x , y );
		if ( mid + 1 <= y ) updrev ( rson , x , y );
		up(p);
	}
	void urev ( int u , int v )
	{
		while ( top[u] != top[v] )
		{
			if ( dep[top[u]] < dep[top[v]] ) swap ( u , v );
			updrev ( 1 , 1 , n , pos[top[u]] , pos[u] );
			u = fa[top[u]];
		}
		if ( dep[u] < dep[v] ) swap ( u , v );
		updrev ( 1 , 1 , n , pos[v] + 1 , pos[u] );
	}

	int querysum ( int p , int l , int r , int x , int y )
	{
		if ( x <= l && r <= y ) return t[p].sum;
		int sum = 0; down(p);
		if ( x <= mid ) sum += querysum ( lson , x , y );
		if ( mid + 1 <= y ) sum += querysum ( rson , x , y );
		return sum;
	}
	int qsum ( int u , int v )
	{
		int res = 0;
		while ( top[u] != top[v] )
		{
			if ( dep[top[u]] < dep[top[v]] ) swap ( u , v );
			res += querysum ( 1 , 1 , n , pos[top[u]] , pos[u] );
			u = fa[top[u]];
		}
		if ( dep[u] < dep[v] ) swap ( u , v );
		res += querysum ( 1 , 1 , n , pos[v] + 1 , pos[u] );
		return res;
	}

	int querymaxx ( int p , int l , int r , int x , int y )
	{
		if ( x <= l && r <= y ) return t[p].maxx;
		int maxx = -inf; down(p);
		if ( x <= mid ) maxx = max ( maxx , querymaxx ( lson , x , y ) );
		if ( mid + 1 <= y ) maxx = max ( maxx , querymaxx ( rson , x , y ) );
		return maxx;
	}
	int qmaxx ( int u , int v )
	{
		int maxx = -inf;
		while ( top[u] != top[v] )
		{
			if ( dep[top[u]] < dep[top[v]] ) swap ( u , v );
			maxx = max ( maxx , querymaxx ( 1 , 1 , n , pos[top[u]] , pos[u] ) );
			u = fa[top[u]];
		}
		if ( dep[u] < dep[v] ) swap ( u , v );
		maxx = max ( maxx , querymaxx ( 1 , 1 , n , pos[v] + 1 , pos[u] ) );
		return maxx;
	}

	int queryminn ( int p , int l , int r , int x , int y )
	{
		if ( x <= l && r <= y ) return t[p].minn;
		int minn = inf; down(p);
		if ( x <= mid ) minn = min ( minn , queryminn ( lson , x , y ) );
		if ( mid + 1 <= y ) minn = min ( minn , queryminn ( rson , x , y ) );
		return minn;
	}
	int qminn ( int u , int v )
	{
		int minn = inf;
		while ( top[u] != top[v] )
		{
			if ( dep[top[u]] < dep[top[v]] ) swap ( u , v );
			minn = min ( minn , queryminn ( 1 , 1 , n , pos[top[u]] , pos[u] ) );
			u = fa[top[u]];
		}
		if ( dep[u] < dep[v] ) swap ( u , v );
		minn = min ( minn , queryminn ( 1 , 1 , n , pos[v] + 1 , pos[u] ) );
		return minn;
	}

}T;


string s;
signed main ()
{
	ios::sync_with_stdio(false);
	cin.tie(0) , cout.tie(0);
	n = read();
	for ( int i = 1 ; i < n ; i ++ ) u[i] = read() + 1 , v[i] = read() + 1 , w[i] = read() , add ( u[i] , v[i] , w[i] ) , add ( v[i] , u[i] , w[i] );
	L.dfs1 ( 1 , 0 ) , L.dfs2 ( 1 , 1 );
	T.build ( 1 , 1 , n );
	m = read();
	for ( int i = 1 , x , y ; i <= m ; i ++ )
	{
		cin >> s;
		switch ( s[0] )
		{
			case 'C' : x = read() , y = read() , T.upd ( 1 , 1 , n , pos[max(u[x],v[x])] , y ); break;
			case 'N' : x = read() + 1 , y = read() + 1 , T.urev ( x , y ); break;
			case 'S' : x = read() + 1 , y = read() + 1 , cout << T.qsum ( x , y ) << endl; break;
			case 'M' : x = read() + 1 , y = read() + 1 , cout << ( s[1] == 'A' ? T.qmaxx ( x , y ) : T.qminn ( x , y ) ) << endl; break;
		}
	}
	return 0;
}

P2486 [SDOI2011] 染色

\(upd\ on\ 10.20:\) 代码全篇重写自己写拍调出来了非常优美的代码() \(csp\ rp++\)

#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
#define inl inline
#define eb emplace_back
#define mid (l+r>>1)
#define ls p<<1
#define rs p<<1|1
#define lson ls,l,mid
#define rson rs,mid+1,r
#define pii pair<int,int>
const int N = 1e5 + 5;

int read ()
{
	int x = 0 , f = 1;
	char ch = cin.get();
	while ( !isdigit ( ch ) ) { if ( ch == '-' ) f = -1; ch = cin.get(); }
	while ( isdigit ( ch ) ) { x = ( x << 1 ) + ( x << 3 ) + ( ch ^ 48 ); ch = cin.get(); }
	return x * f;
}

int n , m , a[N];

int sz[N] , fa[N] , dep[N] , son[N];
int pos[N] , rev[N] , top[N] , timer;

vector<int> e[N];
inl void add ( int u , int v ) { e[u].eb(v); }
struct LCA
{
	void dfs1 ( int u , int ff )
	{
		sz[u] = 1 , fa[u] = ff , dep[u] = dep[ff] + 1;
		for ( auto v : e[u] )
			if ( v ^ ff )
			{
				dfs1 ( v , u );
				sz[u] += sz[v];
				if ( sz[son[u]] < sz[v] ) son[u] = v;
			}
	}
	void dfs2 ( int u , int tp )
	{
		top[u] = tp , pos[u] = ++ timer , rev[timer] = u;
		if ( son[u] ) dfs2 ( son[u] , tp );
		for ( auto v : e[u] ) if ( v ^ fa[u] && v ^ son[u] ) dfs2 ( v , v );
	}
}L;

struct Tree
{
	struct node { int lc , rc , sum , cov; node() { lc = rc = sum = cov = 0; } node ( int lc , int rc , int sum , int cov ) { this->lc = lc , this->rc = rc , this->sum = sum , this->cov = cov; } } t[N<<2];
	inl node merge ( const node &a , const node &b )
	{
		if ( !a.sum ) return b;
		if ( !b.sum ) return a;
		node res;
		res.lc = a.lc , res.rc = b.rc;
		res.sum = a.sum + b.sum;
		if ( a.rc == b.lc ) res.sum --;
		return res;
	}
	inl void pushcol ( int p , int val ) { t[p] = (node){ val , val , 1 , val }; }
	inl void down ( int p ) { if ( t[p].cov ) pushcol ( ls , t[p].cov ) , pushcol ( rs , t[p].cov ) , t[p].cov = 0; }
	inl void up ( int p ) { t[p] = merge ( t[ls] , t[rs] ); }
	void build ( int p , int l , int r )
	{
		if ( l == r ) return t[p] = (node){ a[rev[l]] , a[rev[l]] , 1 , 0 } , void();
		build ( lson ) , build ( rson ) , up(p);
	}
	void upd ( int p , int l , int r , int x , int y , int val )
	{
		if ( x <= l && r <= y ) return pushcol(p,val);
		down(p);
		if ( x <= mid ) upd ( lson , x , y , val );
		if ( mid + 1 <= y ) upd ( rson , x , y , val );
		up(p);
	}
	node query ( int p , int l , int r , int x , int y )
	{
		//cout << p << ' ' << l << ' ' << r << ' ' << x << ' ' << y << endl;
		if ( x <= l && r <= y ) return t[p];
		node res; down(p);
		if ( y <= mid ) return query ( lson , x , y );
		else if ( mid + 1 <= x ) return query ( rson , x , y );
		else return merge ( query ( lson , x , y ) , query ( rson , x , y ) );
	}

	void updcol ( int u , int v , int w )
	{
		while ( top[u] != top[v] )
		{
			if ( dep[top[u]] < dep[top[v]] ) swap ( u , v );
			upd ( 1 , 1 , n , pos[top[u]] , pos[u] , w );
			u = fa[top[u]];
		}
		if ( dep[u] < dep[v] ) swap ( u , v );
		upd ( 1 , 1 , n , pos[v] , pos[u] , w );
	}
	
	int querycol ( int u , int v )
	{
		node resu , resv;
		while ( top[u] != top[v] )
		{
			if ( dep[top[u]] < dep[top[v]] )
			{
				resv = merge ( query ( 1 , 1 , n , pos[top[v]] , pos[v] ) , resv );
				v = fa[top[v]];
			}
			else
			{
				resu = merge ( query ( 1 , 1 , n , pos[top[u]] , pos[u] ) , resu );
				u = fa[top[u]];
			}
		}
		//cout << "OK" << u << ' ' << v << endl;
		//cout << "OK" << pos[u] << ' ' << pos[v] << endl;
		//cout << resu.sum << ' ' << resu.lc << ' ' << resu.rc << endl;
		//cout << query ( 1 , 1 , n , pos[v] , pos[u] ).sum << endl;
		if ( dep[u] < dep[v] ) resv = merge ( query ( 1 , 1 , n , pos[u] , pos[v] ) , resv );
		else resu = merge ( query ( 1 , 1 , n , pos[v] , pos[u] ) , resu );
		//cout << resu.sum << ' ' << resu.lc << ' ' << resu.rc << endl;
		swap ( resu.lc , resu.rc );
		return merge ( resu , resv ).sum;
	}
}T;

char op;
signed main ()
{
	//freopen ( "gen.in" , "r" , stdin );
	//freopen ( "zhengjie.out" , "w" , stdout );
	ios::sync_with_stdio(false);
	cin.tie(0) , cout.tie(0);
	n = read() , m = read();
	for ( int i = 1 ; i <= n ; i ++ ) a[i] = read();
	for ( int i = 1 , u , v ; i < n ; i ++ ) u = read() , v = read() , add ( u , v ) , add ( v , u );
	L.dfs1 ( 1 , 0 ) , L.dfs2 ( 1 , 1 ) , T.build ( 1 , 1 , n );
	//for ( int i = 1 ; i <= n ; i ++ ) cout << dep[i] << ' '; cout << endl;
	//for ( int i = 1 ; i <= n ; i ++ ) cout << top[i] << ' '; cout << endl;
	//for ( int i = 1 ; i <= n ; i ++ ) cout << fa[i] << ' '; cout << endl;
	for ( int i = 1 ; i <= m ; i ++ )
	{
		cin >> op;
		int u = read() , v = read() , w;
		if ( op == 'C' ) w = read() , T.updcol ( u , v , w );
		else cout << T.querycol ( u , v ) << endl;
	}
	return 0;
}

P7735 [NOI2021] 轻重边

\(1h\)写完了

请教一下 \(xz\_w\) 发现题没审明白重构了 \(1h\) 过了样例

卡在 \(45pts\) \(1h\) 最后与 \(bot\) 代码文本比对发现查询挂了() 非常玄妙的题目转化和构造方法()

我们可以将这个题转化为树上查询两点之间同色相邻点对的数目

这样我们对于每一次修改操作将这段路径上的点赋值为一个从未出现过的权值

这样我们保证了路径上的所有重边都是相邻的同色点对那么对这个东西进行计数即可

新学习了查询的写法结构体创造的时候需要使用构造函数

#include<bits/stdc++.h>
using namespace std;
#define mid ((l+r)>>1)
#define inl inline
#define eb emplace_back
#define endl '\n'
#define ls p<<1
#define rs p<<1|1
#define lson ls,l,mid
#define rson rs,mid+1,r
#define pii pair<int,int>
#define fi first
#define se second
#define mkp make_pair
#define print(x) cerr<<#x<<'='<<x<<endl
#define getchar() cin.get()
const int N = 1e5 + 5;
int read()
{
	int x = 0 , f = 1;
	char ch = getchar();
	while ( !isdigit(ch) ) { if ( ch == '-' ) f = -1; ch = getchar(); }
	while ( isdigit(ch) ) { x = ( x << 1 ) + ( x << 3 ) + ( ch ^ 48 ); ch = getchar(); }
	return x * f;
}

int n , m;

vector<int> e[N];
inl void add ( int u , int v ) { e[u].eb(v); }

int sz[N] , son[N] , dep[N] , fa[N];
int timer , rev[N] , pos[N] , top[N];

struct LCA
{
	void dfs1 ( int u , int ff )
	{
		dep[u] = dep[ff] + 1 , fa[u] = ff , sz[u] = 1;
		for ( auto v : e[u] )
			if ( v ^ ff )
			{
				dfs1 ( v , u );
				sz[u] += sz[v];
				if ( sz[son[u]] < sz[v] ) son[u] = v;
			}
	}
	void dfs2 ( int u , int tp )
	{
		top[u] = tp , pos[u] = ++timer , rev[timer] = u;
		if ( son[u] ) dfs2 ( son[u] , tp );
		for ( auto v : e[u] ) if ( v != fa[u] && v != son[u] ) dfs2 ( v , v );
	}
}L;

struct Tree
{
	struct node
	{
		int lc , rc , sum , cov;
		node() { lc = rc = sum = cov = 0; }
		node ( int lc , int rc , int sum , int cov ) { this->lc = lc , this->rc = rc , this->sum = sum , this->cov = cov; }
	} t[N<<2];//区间内同色相邻点对个数
	inl void pushcov ( int p , int l , int r , int val ) { t[p].cov = t[p].lc = t[p].rc = val , t[p].sum = r - l; }
	inl void down ( int p , int l , int r ) { if ( t[p].cov ) pushcov ( lson , t[p].cov ) , pushcov ( rson , t[p].cov ) , t[p].cov = 0; }
	inl node merge ( node u , node v ) { node res; res.lc = u.lc , res.rc = v.rc; res.sum = u.sum + v.sum + ( u.rc == v.lc ); return res; }
	inl void up ( int p ) { t[p] = merge ( t[ls] , t[rs] ); }
	void build ( int p , int l , int r )
	{
		if ( l == r ) return t[p] = { -l , -l , 0 , 0 } , void();
		build ( lson ) , build ( rson ) , up(p);
	}
	void upd ( int p , int l , int r , int x , int y , int val )
	{
		if ( x <= l && r <= y ) return pushcov ( p , l , r , val );
		down(p,l,r);
		if ( x <= mid ) upd ( lson , x , y , val );
		if ( mid + 1 <= y ) upd ( rson , x , y , val );
		up(p);
	}
	void updsum ( int u , int v , int w )
	{
		while ( top[u] != top[v] )
		{
			if ( dep[top[u]] < dep[top[v]] ) swap ( u , v );
			upd ( 1 , 1 , n , pos[top[u]] , pos[u] , w );
			u = fa[top[u]];
		}
		if ( dep[u] < dep[v] ) swap ( u , v );
		upd ( 1 , 1 , n , pos[v] , pos[u] , w );
	}
	node query ( int p , int l , int r , int x , int y )
	{
		if ( x <= l && r <= y ) return t[p];
		down(p,l,r);
		if ( y <= mid ) return query ( lson , x , y );
		else if ( mid + 1 <= x ) return query ( rson , x , y );
		else return merge ( query ( lson , x , y ) , query ( rson , x , y ) );
	}
	int querysum ( int u , int v )
	{
		node resu , resv;
		while ( top[u] != top[v] )
		{
			if ( dep[top[u]] < dep[top[v]] ) resv = merge ( query ( 1 , 1 , n , pos[top[v]] , pos[v] ) , resv ); v = fa[top[v]];
			else resu = merge ( query ( 1 , 1 , n , pos[top[u]] , pos[u] ) , resu ) , u = fa[top[u]];
		}
		if ( dep[u] < dep[v] ) resv = merge ( query ( 1 , 1 , n , pos[u] , pos[v] ) , resv );
		else resu = merge ( query ( 1 , 1 , n , pos[v] , pos[u] ) , resu );
		swap ( resu.lc , resu.rc );
		return merge ( resu , resv ).sum;
	}
}T;

void init()
{
	timer = 0;
	memset ( son , 0 , sizeof son );
	for ( int i = 1 ; i <= n ; i ++ ) e[i].clear();
	memset ( T.t , 0 , sizeof T.t );
}

signed main ()
{
	ios::sync_with_stdio(false);
	cin.tie(0) , cout.tie(0);
	int TT = read();
	while ( TT -- )
	{
		init();
		n = read() , m = read();
		for ( int i = 1 , u , v ; i < n ; i ++ ) u = read() , v = read() , add ( u , v ) , add ( v , u );
		L.dfs1 ( 1 , 0 ) , L.dfs2 ( 1 , 1 ) , T.build ( 1 , 1 , n );
		for ( int i = 1 ; i <= m ; i ++ )
		{
			int op = read() , u = read() , v = read();
			if ( op == 1 ) T.updsum ( u , v , i );
			else cout << T.querysum ( u , v ) << endl;
		}
	}
	return 0;
}

posted @ 2023-08-11 19:58 Echo_Long 阅读(11) 评论(0) 编辑收藏举报

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