24点游戏算法 （无脑递归暴力破解）

7 2 1 10

true

#include <bits/stdc++.h>
using namespace std;

bool is24(vector<double> a,double result)
{
    int sum = 24;
    if(a.empty())
    {
        return result == sum;
    }
    for (int i = 0; i < a.size(); i++)
    {
        vector<double> b(a);
        b.erase(b.begin()+i);
        if(is24(b,result+a[i])||is24(b,result-a[i])||is24(b,result*a[i])||is24(b,result/a[i]))
        {
            return true;
        }
    }
    return false;
}

int main()
{
    vector<double> a(4);
    while(cin >> a[0] >> a[1] >> a[2] >> a[3])
    {
        if(is24(a,0))
        {
            cout << "true" << endl;
        }
        else
        {
            cout << "false" << endl;
        }
    }
    return 0;
}