P3384 【模板】树链剖分

注意

自己理解着打了一遍，注意两个点跳跃的时候，是比较两个点对应链顶的深度

 

#include <algorithm>
#include <iterator>
#include <iostream>
#include <cstring>
#include <cstdlib>
#include <iomanip>
#include <bitset>
#include <cctype>
#include <cstdio>
#include <string>
#include <vector>
#include <stack>
#include <cmath>
#include <queue>
#include <list>
#include <map>
#include <set>
#include <cassert>

using namespace std;
#define lson (l, mid, rt << 1)
#define rson (mid + 1, r, rt << 1 | 1)
#define debug(x) cerr << #x << " = " << x << "\n";
#define pb push_back
#define pq priority_queue

typedef long long ll;
typedef unsigned long long ull;
//typedef __int128 bll;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;
typedef pair<int, pii> p3;

//priority_queue<int> q;//这是一个大根堆q
//priority_queue<int,vector<int>,greater<int> >q;//这是一个小根堆q
#define fi first
#define se second
//#define endl '\n'

#define boost                    \
    ios::sync_with_stdio(false); \
    cin.tie(0)
#define rep(a, b, c) for (int a = (b); a <= (c); ++a)
#define max3(a, b, c) max(max(a, b), c);
#define min3(a, b, c) min(min(a, b), c);

const ll oo = 1ll << 17;
const ll mos = 0x7FFFFFFF;  //2147483647
const ll nmos = 0x80000000; //-2147483648
const int inf = 0x3f3f3f3f;
const ll inff = 0x3f3f3f3f3f3f3f3f; //18
const ll mod = 2147483648;
const double esp = 1e-8;
const double PI = acos(-1.0);
const double PHI = 0.61803399; //黄金分割点
const double tPHI = 0.38196601;

template <typename T>
inline T read(T &x) {
    x = 0;
    int f = 0;
    char ch = getchar();
    while (ch < '0' || ch > '9') f |= (ch == '-'), ch = getchar();
    while (ch >= '0' && ch <= '9') x = x * 10 + ch - '0', ch = getchar();
    return x = f ? -x : x;
}

inline void cmax(int &x, int y) {
    if (x < y) x = y;
}
inline void cmax(ll &x, ll y) {
    if (x < y) x = y;
}
inline void cmin(int &x, int y) {
    if (x > y) x = y;
}
inline void cmin(ll &x, ll y) {
    if (x > y) x = y;
}

/*-----------------------showtime----------------------*/
const int maxn = 1e6 + 9;
int n, m, R, P;
int a[maxn];
vector<int> mp[maxn];

int dp[maxn], fa[maxn], son[maxn], sz[maxn];

void dfs1(int u, int f, int deep) {
    int mx = 0;
    dp[u] = deep;
    sz[u] = 1;
    fa[u] = f;

    for (int i = 0; i < mp[u].size(); i++) {
        int v = mp[u][i];
        if (f == v) continue;
        dfs1(v, u, deep + 1);
        sz[u] += sz[v];
        if (sz[v] > mx) son[u] = v, mx = sz[v];
    }
}
int b[maxn];
int id[maxn], top[maxn];
int cnt = 0;
void dfs2(int u, int f, int topf) {
    id[u] = ++cnt;
    top[u] = topf;
    b[cnt] = a[u];
    if (son[u]) dfs2(son[u], u, topf);

    for (int i = 0; i < mp[u].size(); i++) {
        int v = mp[u][i];
        if (f == v || son[u] == v) continue;
        dfs2(v, u, v);
    }
}
int sum[maxn << 2], lazy[maxn << 2];
void build(int l, int r, int rt) {
    if (l == r) {
        sum[rt] = b[l];
        return;
    }
    int mid = (l + r) >> 1;
    build(l, mid, rt << 1);
    build(mid + 1, r, rt << 1 | 1);
    sum[rt] = (sum[rt << 1] + sum[rt << 1 | 1]) % P;
}
void pushdown(int l, int r, int rt) {
    int mid = (l + r) >> 1;
    lazy[rt << 1] = (lazy[rt << 1] + lazy[rt]) % P;
    lazy[rt << 1 | 1] = (lazy[rt << 1 | 1] + lazy[rt]) % P;
    sum[rt << 1] = (sum[rt << 1] + (mid - l + 1) * lazy[rt]) % P;
    sum[rt << 1 | 1] = (sum[rt << 1 | 1] + (r - mid) * lazy[rt]) % P;
    lazy[rt] = 0;
}
void update(int L, int R, int val, int l, int r, int rt) {
    if (l >= L && r <= R) {
        lazy[rt] = (lazy[rt] + val) % P;
        sum[rt] = (sum[rt] + (r - l + 1) * val) % P;
        return;
    }
    int mid = (l + r) >> 1;
    if (lazy[rt]) pushdown(l, r, rt);
    if (mid >= L) update(L, R, val, l, mid, rt << 1);
    if (mid < R) update(L, R, val, mid + 1, r, rt << 1 | 1);
    sum[rt] = (sum[rt << 1] + sum[rt << 1 | 1]) % P;
}
int query(int L, int R, int l, int r, int rt) {
    if (l >= L && r <= R) {
        return sum[rt];
    }
    int res = 0;
    int mid = (l + r) >> 1;
    if (lazy[rt]) pushdown(l, r, rt);
    if (mid >= L) res = (res + query(L, R, l, mid, rt << 1)) % P;
    if (mid < R) res = (res + query(L, R, mid + 1, r, rt << 1 | 1)) % P;
    sum[rt] = (sum[rt << 1] + sum[rt << 1 | 1]) % P;
    return res;
}
void add1(int x, int y, int z) {
    while (top[x] != top[y]) {
        if (dp[top[x]] < dp[top[y]]) swap(x, y);
        update(id[top[x]], id[x], z, 1, n, 1);
        x = fa[top[x]];
    }
    if (dp[x] > dp[y]) swap(x, y);
    update(id[x], id[y], z, 1, n, 1);
}
int getsum1(int x, int y) {
    int res = 0;
    while (top[x] != top[y]) {
        if (dp[top[x]] < dp[top[y]]) swap(x, y);
        res = (res + query(id[top[x]], id[x], 1, n, 1)) % P;
        x = fa[top[x]];
    }
    if (dp[x] > dp[y]) swap(x, y);
    res = (res + query(id[x], id[y], 1, n, 1)) % P;
    return res;
}
void add2(int x, int z) {
    update(id[x], id[x] + sz[x] - 1, z, 1, n, 1);
}
int getsum2(int x) {
    return query(id[x], id[x] + sz[x] - 1, 1, n, 1);
}
int main() {
    scanf("%d%d%d%d", &n, &m, &R, &P);
    rep(i, 1, n) scanf("%d", &a[i]);
    rep(i, 1, n - 1) {
        int u, v;
        scanf("%d%d", &u, &v);
        mp[u].pb(v);
        mp[v].pb(u);
    }
    dfs1(R, R, 1);
    dfs2(R, R, R);
    build(1, n, 1);

    while (m--) {
        int op;
        scanf("%d", &op);
        if (op == 1) {
            int x, y, z;
            scanf("%d%d%d", &x, &y, &z);
            add1(x, y, z);
        } else if (op == 2) {
            int x, y;
            scanf("%d%d", &x, &y);
            printf("%d\n", getsum1(x, y));
        } else if (op == 3) {
            int x, z;
            scanf("%d%d", &x, &z);
            add2(x, z);
        } else if (op == 4) {
            int x;
            scanf("%d", &x);
            printf("%d\n", getsum2(x));
        }
    }
    return 0;
}