You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
34 lines
569 B
34 lines
569 B
#include <bits/stdc++.h>
|
|
|
|
using namespace std;
|
|
const int N = 110;
|
|
int a[N];
|
|
int n, m;
|
|
int cnt;
|
|
|
|
/**
|
|
测试数据：
|
|
5 1
|
|
答案：
|
|
3
|
|
*/
|
|
void dfs(int step, int sum1, int sum2) {
|
|
//收集答案
|
|
if (step == n + 1) {
|
|
if (sum1 - sum2 == m) cnt++;
|
|
return;
|
|
}
|
|
//选择了当前的数字
|
|
dfs(step + 1, sum1 + a[step], sum2);
|
|
|
|
//放弃了当前的数字
|
|
dfs(step + 1, sum1, sum2 + a[step]);
|
|
}
|
|
|
|
int main() {
|
|
cin >> n >> m;
|
|
for (int i = 1; i <= n; i++) a[i] = i;
|
|
dfs(1, 0, 0);
|
|
cout << cnt << endl;
|
|
return 0;
|
|
} |