24点游戏

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
typedef struct BiTNode
{
    char date[4];
    struct BiTNode *lchild, *rchild;
}BiTNode, *BiTree;

int creB(BiTree &Q)
{
    Q = new BiTNode;
    if (~scanf_s("%s", Q->date, 4) && Q->date[0] != '#')
    {
        if (Q->date[0] == '#')
            Q = NULL;
        else
        {
            creB(Q->lchild);
            creB(Q->rchild);
        }
        return 1;
    }
    Q = NULL;
    return -1;
}

double get_num(char *a)
{
    int length;
    int i;
    double result = 0;
    if (a[0] == 'A')
        return 1;
    else if (a[0] == 'J')
        return 11;
    else if (a[0] == 'Q')
        return 12;
    else if (a[0] == 'K')
        return 13;
    else
    {
        length = strlen(a);
        for (i = 0; i < length; i++)
        {
            result = result * 10 + a[i] - '0';
        }
    }
    return result;
}

double priB(BiTree Q)
{
    double num = 0;
    if (Q == NULL)
        return num;
    if (Q->date[0] == '/' || Q->date[0] == '*' || Q->date[0] == '-' || Q->date[0] == '+')
    {
        double i, j;
        i = priB(Q->lchild);
        j = priB(Q->rchild);
        switch (Q->date[0])
        {
        case '+':
            num = i + j;
            break;
        case '-':
            num = i - j;
            break;
        case '/':
            if (i == 0 || j == 0)
                return 0;
            num = i / j;
            break;
        case '*':
            num = i * j;
            break;
        }
    }
    else
        return get_num(Q->date);
    return num;
}

void priA(BiTree Q)
{

    if (Q == NULL)
        return;
    if (Q->date[0] == '/' || Q->date[0] == '*' || Q->date[0] == '-' || Q->date[0] == '+')
    {
        printf("(");
        priA(Q->lchild);
        printf("%s", Q->date);
        priA(Q->rchild);
        printf(")");
    }
    else
        printf("%s", Q->date);
}


int main()
{
    BiTree Q;
    while (creB(Q) == 1)
    {
        double k;
        k = priB(Q);
        if (k ==24||k== 23.999999999999989)
        {
            priA(Q);
            printf("=%d\n", 24);
        }
        else
            printf("NO\n");
    }
    return 0;
}