luogu3755 [CQOI2017]老C的任务

扫描线水题。

#include <algorithm>
#include <iostream>
#include <cstdio>
using namespace std;
typedef long long ll;
int n, m, dx[300005], dy[300005], cntx, cnty, cnt, uu, vv, ww, aa, bb;
ll ans[100005], c[300005];
struct Node{
	int idd, val, xxx, yyy;
}nd[500005];
bool cmp(Node x, Node y){
	if(x.xxx==y.xxx)	return x.idd<y.idd;
	else	return x.xxx<y.xxx;
}
int lb(int x){
	return x&-x;
}
void add(int pos, int w){
	for(int i=pos; i<=cnty; i+=lb(i))
		c[i] += w;
}
ll query(int pos){
	ll re=0;
	for(int i=pos; i; i-=lb(i))
		re += c[i];
	return re;
}
int main(){
	cin>>n>>m;
	for(int i=1; i<=n; i++){
		scanf("%d %d %d", &uu, &vv, &ww);
		nd[++cnt] = (Node){0, ww, uu, vv};
		dx[++cntx] = uu;
		dy[++cnty] = vv;
	}
	for(int i=1; i<=m; i++){
		scanf("%d %d %d %d", &uu, &vv, &aa, &bb);
		uu--; vv--;
		dx[++cntx] = uu; dx[++cntx] = aa;
		dy[++cnty] = vv; dy[++cnty] = bb;
		nd[++cnt] = (Node){i, 1, uu, vv};
		nd[++cnt] = (Node){i, -1, uu, bb};
		nd[++cnt] = (Node){i, -1, aa, vv};
		nd[++cnt] = (Node){i, 1, aa, bb};
	}
	sort(dx+1, dx+1+cntx);
	sort(dy+1, dy+1+cnty);
	cntx = unique(dx+1, dx+1+cntx) - (dx + 1);
	cnty = unique(dy+1, dy+1+cnty) - (dy + 1);
	for(int i=1; i<=cnt; i++){
		nd[i].xxx = lower_bound(dx+1, dx+1+cntx, nd[i].xxx) - dx;
		nd[i].yyy = lower_bound(dy+1, dy+1+cnty, nd[i].yyy) - dy;
	}
	sort(nd+1, nd+1+cnt, cmp);
	for(int i=1; i<=cnt; i++){
		if(!nd[i].idd)	add(nd[i].yyy, nd[i].val);
		else	ans[nd[i].idd] += query(nd[i].yyy) * nd[i].val;
	}
	for(int i=1; i<=m; i++)
		printf("%lld\n", ans[i]);
	return 0;
}