hdu1556 Color the Ball

#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <iostream>

using namespace std;

const int MAXN = 100010;
int c[MAXN];

int lowbit(int x) {
return x & (-x);
}

int Sum(int n) {
int sum = 0;
while (n > 0) {
sum += c
;
n -= lowbit(n);
}
return sum;
}

void add(int i, int x, int n) {
while (i <= n) {
c[i] += x;
i += lowbit(i);
}
}

int main()
{
int N, i;
int a, b;
int sizec = sizeof(c);
while (scanf("%d", &N) && N) {
memset(c, 0, sizec);     ///用于标记涂色次数
for (i = 1; i <= N; i++) {
scanf("%d%d", &a, &b);

/*  重点  */
add(a, 1, N);       ///从左端点开始向后涂色
add(b + 1, -1, N);   ///从右端点开始向后的反涂色，将左端点涂越界的区间涂回去

///两步结束后已将将涂色区间存入树

}

///由于树状数组的结构特性，此时区间求和结果即为点涂色次数
for (i = 1; i < N; i++) {
printf("%d ", Sum(i));
}
printf("%d\n", Sum(N));
}

return 0;
}