poj_2352树状数组

#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;
int n;
int a[32001];
int lev[15001];
int lowbit(int x)
{
return x&(-x);
}
int sum(int x)
{
int ret=0;
while(x>0)
{
ret+=a[x];
x-=lowbit(x);
}
return ret;
}
void add(int x,int d)
{
while(x<=32001)
{
a[x]+=d;
if(x!=0)
x+=lowbit(x);
else break;
}
}
int main()
{

while(scanf("%d",&n)!=EOF){
memset(a,0,sizeof(a));
memset(lev,0,sizeof(lev));
int b,c;
for(int i=0; i<n; i++)
{
scanf("%d%d",&b,&c);
//add(b,1);
b++;
lev[sum(b)]++;
add(b,1);
}
for(int i=0; i<n; i++)
printf("%d\n",lev[i]);
}
return 0;
}