pku2352——Stars（经典树状数组的应用）

/*
* File: main.cpp
* Author: Administrator
*
* Created on 2010年1月25日, 上午11:05
*/

#include <stdlib.h>
#include<iostream>
using namespace std;
#define N 32005
int in
, a
;
int n = N;

int Lowbit(int x)//x转化为二进制时末尾0的个数
{
return (x & (x^(x - 1)));
}

void Modify(int pos, int num) {
while (pos <= n) {
in[pos] += num;
pos += Lowbit(pos);
}
}

int Sum(int end) {
int sum = 0;
while (end > 0) {
sum += in[end];
end -= Lowbit(end);
}
return sum;
}

/*
*
*/
int main(int argc, char** argv) {

int a1, a2, i, j, m;
while (cin >> m) {
for (i = 1; i <= n; i++) {
in[i] = a[i] = 0;
}
for (i = 1; i <= m; i++) {
cin >> a1 >> a2;
a[Sum(a1 + 1)]++;
Modify(a1 + 1, 1);
}
for (i = 0; i < m; i++) {
cout << a[i] << endl;
}
}
return (EXIT_SUCCESS);
}