题解 | #分割等和子集# dfs

#include <iostream>
#include <cstring>
using namespace std;
const int N = 510;
int arr[N], n, target;
bool dfs(int sum, int i)
{
    if(sum == target) return true;
    if(i == n || sum > target) return false;
    return dfs(arr[i] + sum, i + 1) || dfs(sum, i + 1); 
}
int main() {
    int sum = 0;
    cin >> n;
    for(int i = 0; i < n; i ++) 
    {
        cin >> arr[i];
        sum += arr[i];
    }
    if(sum & 1) cout << "false";
    else
    {
        target = sum / 2;
        if(dfs(0, 0)) cout << "true";
        else cout << "false";
    }

}
// 64 位输出请用 printf("%lld")