华为oj_24点游戏算法

#include <iostream>
#include <cmath>

using namespace std;

const int R=24;
const double E=0.000001;

bool ishege(double a,int d)
{
    if((fabs(a+d-R)<E)||(fabs(a-d-R)<E)||(fabs(d-a-R)<E)||(fabs(a*d-R)<E)||(fabs(a/d-R)<E)||(fabs(d/a-R)<E))
        return true;
    return false;
}

bool ishege(double da,int c,int d)
{
    double db=c;
    double r1=da/db;
    double r2=db/da;
    double r3=da-db;
    double r4=db-da;
    double r5=da+db;
    double r6=da*db;
    if(ishege(r1,d)||ishege(r2,d)||ishege(r3,d)||ishege(r4,d)||ishege(r5,d)||ishege(r6,d))
        return true;
    return false;
}

bool ishege(int a,int b,int c,int d)
{
    double da=a;
    double db=b;
    double r1=da/db;
    double r2=db/da;
    double r3=da-db;
    double r4=db-da;
    double r5=da+db;
    double r6=da*db;
    if(ishege(r1,c,d)||ishege(r2,c,d)||ishege(r3,c,d)||ishege(r4,c,d)||ishege(r5,c,d)||ishege(r6,c,d))
        return true;

    return false;
}
int main()
{
    int a,b,c,d;
    while(cin>>a>>b>>c>>d)
    {
        if(ishege(a,b,c,d)||ishege(a,c,b,d)||ishege(a,d,c,b)||ishege(c,b,a,d)||ishege(d,b,c,a)||ishege(c,d,a,b))
            cout << "true" << endl;
        else
            cout << "false" << endl;
    }
    return 0;
}

这道题目很有意思！！！

可惜我没有想到方便的做法。。。