BZOJ 1935 Tree 园丁的烦恼 [差分][树状数组]

#include<cstdio>#include<algorithm>using namespace std;#define N 500005#define X 10000005inline int in(int x=0,char ch=getchar()){while(ch>'9'||ch<'0') ch=getchar();    while(ch>='0'&&ch<='9') x=(x<<3)+(x<<1)+ch-'0',ch=getchar();return x;}struct Point{int x,y;}p[N];struct Qus{int x,y,f,id;}q[N<<2];inline bool operator < (const Point &a,const Point &b){return a.x<b.x;}inline bool operator < (const Qus &a,const Qus &b){return a.x<b.x||(a.x==b.x&&a.y<b.y);}int ans[N];int n,m,cnt;int d[X];inline void Add(int x){for(;x<X;x+=x&-x) d[x]++;}inline int Sum(int x,int res=0){for(;x;x-=x&-x) res+=d[x];return res;}int main(){    n=in(),m=in();int x1,y1,x2,y2;    for(int i=1;i<=n;i++) p[i].x=in()+1,p[i].y=in()+1;    for(int i=1;i<=m;i++){        x1=in()+1,y1=in()+1,x2=in()+1,y2=in()+1;        q[++cnt]=(Qus){x1-1,y1-1,1,i};        q[++cnt]=(Qus){x1-1,y2,-1,i};        q[++cnt]=(Qus){x2,y1-1,-1,i};        q[++cnt]=(Qus){x2,y2,1,i};    }    sort(p+1,p+n+1);sort(q+1,q+cnt+1);    for(int i=1,j=1;i<=cnt;i++){        for(;j<=n&&p[j].x<=q[i].x;j++) Add(p[j].y);        ans[q[i].id]+=Sum(q[i].y)*q[i].f;    }    for(int i=1;i<=m;i++) printf("%d\n",ans[i]);    return 0;}