poj2841

写个树状数组板子，存一下。

#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
const int N=100005;
struct point {
    int x,y,id;
}p[N];
int n,c[N],res[N];
bool cmp(point a,point b) {
    if (a.y!=b.y)
        return a.y>b.y;
    return a.x<b.x;
}
int lowbit(int x) {
    return x&(-x);
}
int sum(int x) {
    int ret=0;
    while (x>0) {
        ret+=c[x];
        x-=lowbit(x);
    }
    return ret;
}
void add(int x,int d) {
    while (x<=N) {
        c[x]+=d;
        x+=lowbit(x);
    }
}
int main() {
    while (scanf("%d",&n)==1&&n) {
        memset(c,0,sizeof(c));
        for (int i=0; i<n; i++) {
            scanf("%d%d",&p[i].x,&p[i].y);
            p[i].x++;
            p[i].y++;
            p[i].id=i;
        }
        sort(p,p+n,cmp);
        for (int i=0; i<n; i++) {
            if (i>0 && p[i-1].x==p[i].x && p[i-1].y==p[i].y)
                res[p[i].id]=res[p[i-1].id];
            else
                res[p[i].id]=sum(p[i].x);
            add(p[i].x,1);
        }
        for (int i=0; i<n-1; i++)
            printf("%d ",res[i]);
        printf("%d
",res[n-1]);
    }
    return 0;
}