2023年中国传媒大学程序设计大赛（同步赛）F.舞台矩形

 

一个简单的线段树维护最值，容易犯错的地方在于y相等的时候不应该省略 这个地方调了一会发现自己傻了

#include
#define ls u<<1
#define rs u<<1|1
using namespace std;
const int N = 1e5+10;
typedef long long ll;
const ll INF = 2e18;
struct Tree{
	int l,r;
	ll mmin,mmax;
}tr[N*4];
int n,m;
vectorvecx;
struct Node{
	int x,y;
}node[N];


void pushup(int u){
	tr[u].mmin = min(tr[u<<1].mmin,tr[u<<1|1].mmin);
	tr[u].mmax = max(tr[u<<1].mmax,tr[u<<1|1].mmax);
}

void build(int u,int l,int r){
	
	tr[u] = {l,r,INF,-INF};
	if(l==r)return;
	
	int mid = l+r>>1;
	build(u<<1,l,mid),build(u<<1|1,mid+1,r);
	pushup(u);
}

ll query1(int u,int l,int r){
	if(l<=tr[u].l&&r>=tr[u].r)return tr[u].mmin;
	
	int mid = tr[u].l+tr[u].r>>1;
	ll res = INF;
	if(l<=mid)res = min(res,query1(u<<1,l,r));
	if(r>mid)res = min(res,query1(u<<1|1,l,r));
	
	return res;
	
}

ll query2(int u,int l,int r){
	if(l<=tr[u].l&&r>=tr[u].r)return tr[u].mmax;
	int mid = tr[u].l+tr[u].r>>1;
	ll res = -INF;
	if(l<=mid)res = max(res,query2(u<<1,l,r));
	if(r>mid)res = max(res,query2(u<<1|1,l,r));
	
	return res;
}

int findx(int x){
	return lower_bound(vecx.begin(),vecx.end(),x)-vecx.begin()+1;
}
void modify(int u,int x, ll c){
	if(tr[u].l == tr[u].r){
		tr[u].mmin = min(tr[u].mmin,c);
		tr[u].mmax = max(tr[u].mmax,c);
		return;
	}
	
	int mid = tr[u].l+tr[u].r>>1;
	if(x<=mid)modify(ls,x,c);
	else modify(rs,x,c);
	pushup(u);
}
int main()
{
	cin>>n;
	for(int i=1;i<=n;i++){
		int x,y;
		cin>>x>>y;
		node[i]={x,y};
		vecx.push_back(x);
	}
	
	

	sort(vecx.begin(),vecx.end());
	vecx.erase(unique(vecx.begin(),vecx.end()),vecx.end());
    build(1,1,100010);
	for(int i=1;i<=n;i++){
	    int x = findx(node[i].x);
	    modify(1,x,node[i].y);
	}
	
	
	
	
	
	int m;
	cin>>m;
	while(m--){
		int id1,id2;
		cin>>id1>>id2;
		auto t1 = node[id1];
		auto t2 = node[id2];
		int x_1 = findx(t1.x);
		int x_2 = findx(t2.x);
		
		if(x_1>=x_2)printf("0\n");
		else{
			ll len = query2(1,x_1,x_2)-query1(1,x_1,x_2);
			ll s = len * abs(t1.x-t2.x);
			printf("%lld\n",s);
		}
	
	}
	
	return 0;
	
	
	
}