HDU ACM 1541 Stars(树状数组)

http://acm.hdu.edu.cn/showproblem.php?pid=1541

#include <iostream>
#include <queue>
using namespace std;
const int MAX = 32000 + 10;
//const int MAXN = 15000 + 10;
int C[MAX];
int Level[MAX];
int n;
int LowBit(int x)
{
    return x & (-x);
}
void Update(int num)
{
    while(num < MAX)
    {
        C[num] += 1;
        num += LowBit(num);
    }
}
int CalSum(int num)
{
    int sum = 0;
    while(num > 0)
    {
        sum += C[num];
        num -= LowBit(num);
    }
    return sum;
}

int main()
{
    int x,y;
    while(scanf("%d",&n)!=EOF)
    {
        int i;
        memset(C,0,sizeof(C));
        memset(Level,0,sizeof(Level));
        for(i=0;i<n;i++)
        {
            scanf("%d%d",&x,&y);
            Level[CalSum(x+1)]++;
            Update(x+1);
        }
        for(i=0;i<n;i++)
        {
            printf("%d\n",Level[i]);
        }
    }
    return 0;
}