Mass Change Queries CodeForces - 911G (线段树合并)

#include <iostream>
#include <algorithm>
#include <cstdio>
#define REP(i,a,n) for(int i=a;i<=n;++i)
#define mid (l+r>>1)
#define lc (o<<1)
#define rc (lc|1)

using namespace std;
typedef long long ll;

const int N = 2e5+10;
int a[N], n, m, t;
int rt[110], tot, ql, qr, now;
struct _ {int l,r;}v[N<<5];

void ins(int &o, int l, int r, int pos) {
	if (!o) o=++tot;
	if (l==r) return;
	if (mid>=pos) ins(v[o].l,l,mid,pos);
	else ins(v[o].r,mid+1,r,pos);
}

int merge(int x, int y) {
	if (!x||!y) return x^y;
	v[x].l = merge(v[x].l,v[y].l);
	v[x].r = merge(v[x].r,v[y].r);
	return x;
}

void update(int &x, int &y, int l, int r) {
	if (!x) return;
	if (ql<=l&&r<=qr) return y=merge(x,y),void(x=0);
	if (!y) y=++tot;
	if (mid>=ql) update(v[x].l,v[y].l,l,mid);
	if (mid<qr) update(v[x].r,v[y].r,mid+1,r);
}

void dfs(int o, int l, int r) {
	if (!o) return;
	if (l==r) return void(a[l]=now);
	dfs(v[o].l,l,mid),dfs(v[o].r,mid+1,r);
}

int main() {
	scanf("%d", &n);
	REP(i,1,n) { 
		int t;
		scanf("%d", &t);
		ins(rt[t],1,n,i);
	}
	scanf("%d", &m);
	while (m--) {
		int x, y;
		scanf("%d%d%d%d", &ql, &qr, &x, &y);
		if (x!=y) update(rt[x],rt[y],1,n);
	}
	REP(i,1,100) now=i,dfs(rt[i],1,n);
	REP(i,1,n) printf("%d ",a[i]);
	puts("");
}