c语言的算24点

c语言的24点计算：

输入为1-9的4个数字，

输出为+-*/()运算之后等于24的所有结果

#include<stdio.h>
#include <string.h>
double counttest(int a1,int a2,int a3,int a4, int b1,int b2,int b3)
{
	double num = 0;
	switch(b1)
	{
		case 0:
			num = a1+a2;
			break;
		case 1:
			num = a1-a2;
			break;
		case 2:
			num = a1*a2;
			break;
		case 3:
			if(a2==0)
				return -1;
			num = (double)a1/((double)a2);
			break;
		default:
			return 1;
	}
//	printf("%lf\n",num);
	switch(b2)
	{
		case 0:
			num = num+a3;
			break;
		case 1:
			num = num-a3;
			break;
		case 2:
			num = num*a3;
			break;
		case 3:
			if(a3==0)
				return -1;
			num = (double)num/((double)a3);
			break;
		default:
			return 1;
	}
//	printf("%lf\n",num);
	switch(b3)
	{
		case 0:
			num = num+a4;
			break;
		case 1:
			num = num-a4;
			break;
		case 2:
			num = num*a4;
			break;
		case 3:
			if(a4==0)
				return -1;
			num = (double)num/((double)a4);
			break;
		default:
			return 1;
	}
//	printf("%lf\n",num);
	return num;
}
#define CAL24POINT_MAX_SIZE	128

int Cal24Point(int x1,int x2,int x3,int x4,char *calRst)
{
	int a[4];
	char cou[4][2] = {"+","-","*","/"};
	char tmp[32];
	int status = 1;
	float num;
	int i = 0;
	int i1 = 0;
	int i2 = 0;
	int i3 = 0;
	int j = 0; 
	int k = 0;
	int cnt = 0;

 //   FunA(1);
    if(0 == calRst)
    {
        return -1;
    }
    memset(calRst,0,CAL24POINT_MAX_SIZE);
    if(((x1 < 0 ) || (x1 > 10 ))
        || ((x2 < 0 ) || (x2 > 10 ))
        || ((x3 < 0 ) || (x3 > 10 ))
        || ((x4 < 0 ) || (x4 > 10 )))
    {
        sprintf(calRst,"Param Err:%d %d %d %d ",x1,x2,x3,x4);
        return -1;
    }
    a[0] = x1;
    a[1] = x2;
    a[2] = x3;
    a[3] = x4;

	num = 0;
	status = 1;

	for(i = 0;(i < 4); i++)
	{
		for(i1 = 0;(i1 < 4); i1++)
		{
			if(i1 == i)
				continue;
			for(i2 = 0;(i2 < 4); i2++)
			{
				if((i2 == i)||(i2 == i1))
					continue;
				for(i3 = 0;(i3 < 4); i3++)
				{
					if((i3 == i)||(i3 == i1)||(i3 == i2))
						continue;
					for(j = 0; (j < 4); j++)
					{
						for(k = 0; (k < 4); k++)
							for(cnt = 0; (cnt < 4); cnt++)
							{
								num = counttest(a[i],a[i1],a[i2],a[i3],j,k,cnt);
								if(num == 24.0)
								{
									if(k>1)
										sprintf(tmp,"(%d %s %d )%s %d %s %d = 24 \n",a[i],cou[j],a[i1],cou[k],a[i2],cou[cnt],a[i3]);
									else if(cnt>1)
										sprintf(tmp,"(%d %s %d %s %d )%s %d = 24 \n",a[i],cou[j],a[i1],cou[k],a[i2],cou[cnt],a[i3]);
									else
										sprintf(tmp,"%d %s %d %s %d %s %d = 24 \n",a[i],cou[j],a[i1],cou[k],a[i2],cou[cnt],a[i3]);
									status=0;

									if(strlen(calRst) + strlen(tmp) >= CAL24POINT_MAX_SIZE)
									{
										return 0;
									}
									strcat(calRst,tmp);
								}
							}
					}
				}
			}
		}
	}
	if(status == 1)
	{
		sprintf(calRst,"Can't find answer %d %d %d %d ",a[0],a[1],a[2],a[3] );
		status=0;
        return 1;
	}
    return 0;
}

int main()
{
	int a = 0, b = 0, c = 0, d = 0;
	char result[CAL24POINT_MAX_SIZE];
	while(1)
	{
		printf("please input 4 value (0 < value < 10)\n");
		scanf("%d %d %d %d",&a,&b,&c,&d);
		Cal24Point(a,b,c,d, result);
		printf("result is :\n%s \n",result);
	}
	return 0;
}