[BZOJ1483] [HNOI2009] 梦幻布丁

题目链接

BZOJ：https://lydsy.com/JudgeOnline/problem.php?id=1483.

洛谷：https://www.luogu.org/problemnew/show/P3201.

Solution

直接上线段树合并就好了，反正数据水，64MB也能过。

话说题解是啥链表启发式合并...还是线段树合并来的实在

#include<bits/stdc++.h>
using namespace std;

void read(int &x) {
    x=0;int f=1;char ch=getchar();
    for(;!isdigit(ch);ch=getchar()) if(ch=='-') f=-f;
    for(;isdigit(ch);ch=getchar()) x=x*10+ch-'0';x*=f;
}

void print(int x) {
    if(x<0) putchar('-'),x=-x;
    if(!x) return ;print(x/10),putchar(x%10+48);
}
void write(int x) {if(!x) putchar('0');else print(x);putchar('\n');}

#define lf double
#define ll long long 

const int maxn = 1e6+10;
const int inf = 1e9;
const lf eps = 1e-8;

int rt[maxn],n,m,ans;

#define mid ((l+r)>>1)

namespace SGT {
	int ls[maxn<<2],rs[maxn<<2],sum[maxn<<2],seg;
	bool L[maxn<<2],R[maxn<<2];
	void update(int p) {
		sum[p]=sum[ls[p]]+sum[rs[p]];L[p]=L[ls[p]],R[p]=R[rs[p]];
		if(R[ls[p]]&&L[rs[p]]) sum[p]--;
	}
	void insert(int &p,int l,int r,int x) {
		if(!p) p=++seg;
		if(l==r) return L[p]=R[p]=1,sum[p]=1,void();
		if(x<=mid) insert(ls[p],l,mid,x);
		else insert(rs[p],mid+1,r,x);
		update(p);
	}
	int query(int x) {return sum[x];}
	int merge(int x,int y) {
		if(!x||!y) return x+y;
		int p=++seg;
		ls[p]=merge(ls[x],ls[y]);
		rs[p]=merge(rs[x],rs[y]);
		update(p);return p;
	}
}

int main() {
	read(n),read(m);
	for(int i=1,x;i<=n;i++) read(x),SGT::insert(rt[x],1,n,i);
	for(int i=1;i<=1e6;i++) if(rt[i]) ans+=SGT::query(rt[i]);
	for(int i=1;i<=m;i++) {
		int op,x,y;read(op);
		if(op==1) {
			read(x),read(y);if(x==y) continue;int a,b;
			ans-=a=(SGT::query(rt[x])+SGT::query(rt[y]));
			rt[y]=SGT::merge(rt[x],rt[y]),rt[x]=0;
			ans+=b=SGT::query(rt[y]);
		} else write(ans);
	}
	return 0;
}