湖南多校对抗赛（2015.05.03）Problem A: Twenty-four point

给四个数 问能不能算出24点。。。我的方法比较烂。。。920ms 差点TLE。应该有更好的方法。

#include<stdio.h>
#include<string.h>
#include<math.h>
#include<algorithm>
using namespace std;
double a[], ff[], n;
double rt[][], yy[];
int sum;
double get(double x, double y, int fu)
{
    if (fu == ) return x + y;
    if (fu == ) return x - y;
    if (fu == ) return x * y;
    if (fu == ) return x / y;
}
void dfs(int tot)
{
    int ii;
    if (tot == )
    {
        rt[sum][] = yy[];
        rt[sum][] = yy[];
        rt[sum][] = yy[];
        rt[sum][] = yy[];
        sum++;
        return;
    }
    for (ii = ; ii < ; ii++)
    {
        if (ff[ii] == )
        {
            ff[ii] = ;
            yy[tot] = a[ii];
            dfs(tot + );
            ff[ii] = ;
        }
    }
}
int main()
{
    while (~scanf("%lf%lf%lf%lf", &a[], &a[], &a[], &a[]))
    {
        memset(ff, , sizeof(ff));
        sum = ; dfs(); int i, j, k, g;
        int ans = ;
        double linshi1 = , linshi2 = , linshi3 = ;
        double z, x, c, v;
        for (i = ; i <= ; i++)
        {
            for (g = ; g <= ; g++)
            {
                for (k = ; k <= ; k++)
                {
                    for (j = ; j <= ; j++)
                    {

                        z = rt[i][]; x = rt[i][]; c = rt[i][]; v = rt[i][];
                        linshi1 = get(z, x, g);
                        linshi2 = get(linshi1, c, k);
                        linshi3 = get(linshi2, v, j);
                        if (fabs(linshi3 - )<0.0000001){ ans = ; break; }

                        linshi1 = get(z, x, g);
                        linshi2 = get(c, v, j);
                        linshi3 = get(linshi1, linshi2, k);
                        if (fabs(linshi3 - )<0.0000001){ ans = ; break; }

                        linshi1 = get(x, c, k);
                        linshi2 = get(z, linshi1, g);
                        linshi3 = get(linshi2, v, j);
                        if (fabs(linshi3 - )<0.0000001){ ans = ; break; }

                        linshi1 = get(x, c, k);
                        linshi2 = get(linshi1, v, j);
                        linshi3 = get(z, linshi2, g);
                        if (fabs(linshi3 - )<0.0000001){ ans = ; break; }

                        linshi1 = get(c, v, j);
                        linshi2 = get(z, x, g);
                        linshi3 = get(linshi1, linshi2, k);
                        if (fabs(linshi3 - )<0.0000001){ ans = ; break; }

                        linshi1 = get(c, v, j);
                        linshi2 = get(x, linshi1, k);
                        linshi3 = get(z, linshi2, g);
                        if (fabs(linshi3 - )<0.0000001){ ans = ; break; }

                    }
                    if (ans) break;
                }
                if (ans) break;
            }
            if (ans) break;
        }
        if (ans == )printf("Yes\n");
        else printf("No\n");
    }
    return ;
}