树状数组

#include<bits/stdc++.h>
using namespace std;
const int N = 32010;
int tr[N],level[N];
int lowbit(int x) {
    return x & (-x);
}
//加操作 i从x~N i+=lowbit(i)
void add(int x, int y) {
    for (int i = x; i < N; i += lowbit(i)) {
        tr[i] += y;
    }
}
//求和操作 i从x~0 i-=lowbit(i)
int sum(int x) {
    int res = 0;
    for (int i = x; i > 0; i-=lowbit(i)) {
        res +=tr[i] ;
    }
    return res;
}
int n;
int main()
{
    cin >> n;
    int temp = n;
    while (n--) {
        int x, y;
        cin >> x >> y;
        x++;
        level[sum(x)]++;
        add(x, 1);
    }

    for (int i = 0; i < temp; i++) {
        cout << level[i] << endl;
    }
    return 0;
}