python/TangDou/LanQiaoBei/LanQiao12XuanBaSaiZhongJi/5.cpp

#include <iostream>

using namespace std;
int n, m;
const int N = 110;
int res;
int a[N];

void dfs(int u) {
    if (u == n + 1) {
        int sum = 0;
        for (int i = 1; i <= n; i++) sum += a[i];
        if (sum == m) {
            res++;
        }
        return;
    }
    for (int i = a[u - 1]; i >= 1; i--) {
        a[u] += i;
        dfs(u + 1);
        a[u] -= i;
    }
}
int main() {
    cin >> n >> m;
    a[0] = m;
    dfs(1);
    cout << res << endl;
    return 0;
}