POJ 2481 Cows

#include <stdio.h>
#include <cstring>
#include <algorithm>
using namespace std;
const int maxn=100005;
int c[maxn+1];
struct point
{
    int s,e,ans,id;
} p[maxn+1];
inline int lowbit(int x)
{
    return x&(-x);
}
void update(int x)
{
    for(int i=x; i<maxn; i+=lowbit(i))
        c[i]+=1;
}
int sum(int x)
{
    int ans=0;
    for(int i=x; i>0; i-=lowbit(i))
        ans+=c[i];
    return ans;
}
int cmp(point a,point b)
{
    if(a.s!=b.s) return a.s<b.s;
    return a.e>b.e;
}
int cmp1(point a,point b)
{
    return a.id<b.id;
}
int main()
{
    int n;
    while(scanf("%d",&n)==1&&n)
    {
        memset(c,0,sizeof(c));
        memset(p,0,sizeof(p));
        for(int i=0; i<n; i++)
            scanf("%d%d",&p[i].s,&p[i].e),p[i].id=i,p[i].s++,p[i].e++;
        sort(p,p+n,cmp);
        for(int i=0; i<n; i++)
        {
            if(i&&p[i].e==p[i-1].e&&p[i].s==p[i-1].s) p[i].ans=p[i-1].ans;
            else p[i].ans=i-sum(p[i].e-1);
            update(p[i].e);
        }
        sort(p,p+n,cmp1);
        for(int i=0; i<n-1; i++)
            printf("%d ",p[i].ans);
        printf("%d\n",p[n-1].ans);
    }
    return 0;
}