POJ 2481 Cows

#include <cstdio>
#include <iostream>
#include <algorithm>
#include <cstring>
using namespace std;

#define rep(i,j,k) for(int i = j;i<=k;i++)
#define Clean(x,y) memset(x,y,sizeof(x))

const int maxn = 100009;
const int m = 100000;

struct node
{
int x,y;
int pos;
}a[maxn];

bool cmp(node a,node b)
{
if ( a.x == b.x ) return a.y > b.y;
return a.x < b.x;
}

int n;
int ans[maxn];
int sum[maxn];
int lowbit(int x)
{
return x&(-x);
}
void add(int x,int k)
{
while(x<=m)
{
sum[x]+=k;
x+=lowbit(x);
}
}
int query(int x)
{
int ans = 0;
while(x)
{
ans+=sum[x];
x-=lowbit(x);
}
return ans;
}

int main()
{
while(cin>>n)
{
if ( !n ) break;
Clean(sum,0);
rep(i,1,n)
{
scanf("%d%d",&a[i].x,&a[i].y);
a[i].pos = i;
}
sort(a+1,a+1+n,cmp);
a[0].x = a[0].y = -1;
rep(i,1,n)
{
if ( a[i].x == a[i-1].x && a[i].y == a[i-1].y )
ans[a[i].pos] = ans[a[i-1].pos];
else
ans[a[i].pos] =  query(m)-query(a[i].y-1) ;
add(a[i].y,1);
}
rep(i,1,n) printf("%d%c",ans[i], ( (i==n)?'\n':' ' ) );

}
return 0;
}