求用c++编写24点游戏万分感谢

Question

1） 随机给出 4 个数字（1~9），要求只用加减乘除判断是否能够算出 24，如果能够算出，需要给出计算过程（需要加括号的地方必须加上括号），如果没有解，则显示“无解！”；
2） 也可以实现用户输入计算表达式，由程序来验证的功能，如果正确，则显示“你真棒！”的结果，否则，显示“输入错误，请重试！”;
3） 程序具有检错功能；
4） 编写菜单系统；

Answer 1

完整代码，还有隐藏模式……输入m列出全部可能的题和答案
VS2019编译通过。

#define _CRT_SECURE_NO_WARNINGS
#include <time.h>
#include <stdlib.h>
#include <iostream>
using namespace std;

int const NUMBERCOUNT = 4;
float const RESULT = 24;
bool isHit = false;

char* ExpressPool;
int PoolIdx;
int MAX_RESULT = 5000;

bool m_mode;

enum OPT {
    PLU,//加
    MIN,//减
    MINBY,//被减
    MUL,//乘
    DIV,//除
    DIVBY//被除
};


float cal(int ncount, float* nums, char* exps)
{

    float a, b;
    if (ncount == 2)
    {
        a = nums[0];
        b = nums[1];

        OPT opt;
        float result = 0.0f;

        for (opt = PLU; opt <= DIVBY; opt = (OPT)(opt + 1))
        {
            switch (opt)
            {
            case PLU:
                result = a + b;
                if (result == RESULT)
                {
                    sprintf(ExpressPool + PoolIdx * 32, "%s+%s", exps, exps + 32);
                    PoolIdx++;
                    sprintf(ExpressPool + PoolIdx * 32, "%s+%s", exps + 32, exps);
                    PoolIdx++;
                    isHit = true;
                }
                break;
            case MIN:
                result = a - b;
                if (result == RESULT)
                {
                    sprintf(ExpressPool + PoolIdx * 32, "%s-%s", exps, exps + 32);
                    PoolIdx++;
                    isHit = true;
                }
                break;
            case MINBY:
                result = b - a;
                if (result == RESULT)
                {
                    sprintf(ExpressPool + PoolIdx * 32, "%s-%s", exps + 32, exps);
                    PoolIdx++;
                    isHit = true;
                }
                break;
            case MUL:
                result = a * b;
                if (result == RESULT)
                {
                    sprintf(ExpressPool + PoolIdx * 32, "%s*%s", exps, exps + 32);
                    PoolIdx++;
                    sprintf(ExpressPool + PoolIdx * 32, "%s*%s", exps + 32, exps);
                    PoolIdx++;
                    isHit = true;
                }
                break;
            case DIV:
                if (b == 0)continue;
                result = a / b;
                if (result == RESULT)
                {
                    sprintf(ExpressPool + PoolIdx * 32, "%s/%s", exps, exps + 32);
                    PoolIdx++;
                    isHit = true;
                }
                break;
            case DIVBY:
                if (a)continue;
                result = b / a;
                if (result == RESULT)
                {
                    sprintf(ExpressPool + PoolIdx * 32, "%s/%s", exps + 32, exps);
                    PoolIdx++;
                    isHit = true;
                }
                break;
            }
        }

    }
    else
    {
        for (int i = 0; i < ncount; i++)
        {
            for (int j = 0; j < ncount; j++)
            {
                if (i != j)
                {
                    int newcount = ncount - 1;
                    float* num = new float[newcount];
                    char* newexps = (char*)malloc(32 * newcount);
                    memset(newexps, 0, 32 * newcount);
                    int idx = 1;
                    for (int m = 0; m < ncount; m++)
                    {
                        if (m != i && m != j)
                        {
                            num[idx] = nums[m];
                            strcpy(newexps + idx * 32, exps + m * 32);
                            idx++;
                        }
                    }
                    OPT opt;
                    for (opt = PLU; opt <= DIVBY; opt = (OPT)(opt + 1))
                    {
                        switch (opt)
                        {
                        case PLU:
                            num[0] = nums[i] + nums[j];
                            sprintf(newexps, "(%s+%s)", exps + i * 32, exps + j * 32);
                            break;
                        case MIN:
                            num[0] = nums[i] - nums[j];
                            sprintf(newexps, "(%s-%s)", exps + i * 32, exps + j * 32);
                            break;
                        case MINBY:
                            num[0] = nums[j] - nums[i];
                            sprintf(newexps, "(%s-%s)", exps + j * 32, exps + i * 32);
                            break;
                        case MUL:
                            num[0] = nums[i] * nums[j];
                            sprintf(newexps, "(%s*%s)", exps + i * 32, exps + j * 32);
                            break;
                        case DIV:
                            if (nums[j] == 0)continue;
                            num[0] = nums[i] / nums[j];
                            sprintf(newexps, "(%s/%s)", exps + i * 32, exps + j * 32);
                            break;
                        case DIVBY:
                            if (nums[i] == 0)continue;
                            num[0] = nums[j] / nums[i];
                            sprintf(newexps, "(%s/%s)", exps + j * 32, exps + i * 32);
                            break;
                        }
                        cal(newcount, num, newexps);
                    }
                }
            }
        }
    }
    return 0;
}

int autoanswer(float* num)
{
    int ret = 0;
    ExpressPool = (char*)malloc(MAX_RESULT * 32);
    memset(ExpressPool, 0, MAX_RESULT * 32);
    PoolIdx = 0;
    char* exps = (char*)malloc(32 * NUMBERCOUNT);
    memset(exps, 0, 32 * NUMBERCOUNT);
    for (int i = 0; i < NUMBERCOUNT; i++)
    {
        if ((exps + i * 32) != 0)
            sprintf(exps + i * 32, "%d", (int)num[i]);
    }
    isHit = false;
    cal(NUMBERCOUNT, num, exps);
    if (!isHit)
    {
        if (!m_mode)
        {
            printf("此题无解！\n");
        }
    }
    else
    {

        for (int i = 0; i < MAX_RESULT; i++)
        {
            char firstchar = *(ExpressPool + i * 32);
            if (firstchar != '\0')
            {
                if (!m_mode)
                {
                    printf("%s = %d\n", ExpressPool + i * 32, (int)RESULT);
                }
                ret++;
                for (int j = i + 1; j < MAX_RESULT; j++)
                {
                    char newfirstchar = *(ExpressPool + j * 32);
                    if (newfirstchar != '\0')
                    {
                        char* str1 = (char*)(ExpressPool + i * 32);
                        char* str2 = (char*)(ExpressPool + j * 32);
                        int cmpresult = strcmp(ExpressPool + i * 32, ExpressPool + j * 32);
                        if (cmpresult == 0)
                        {
                            memset(ExpressPool + j * 32, '\0', 32);
                        }
                    }
                }
            }
        }
    }
    return ret;
}


int main() {
    float num[NUMBERCOUNT];
    srand((unsigned int)(time(NULL)));
    char c;
    printf("\n\n");
    printf("**********************************************************\n");
    printf("*                                                        *\n");
    printf("*                        计算24游戏                      *\n");
    printf("*                                                        *\n");
    printf("*    随机产生4个(0-9)的数字，判断是否能通过+-*/得到24    *\n");
    printf("*                                                        *\n");
    printf("*                        茂大叔提供                      *\n");
    printf("*                                                        *\n");
    printf("**********************************************************\n\n");
    printf("[enter]=随机计算;a=用户答题;q=退出\n");
    printf("请输入命令：");
    c = getchar();
    while (c != 'q') {
        m_mode = false;
        printf("备选数字为:");
        for (int i = 0; i < NUMBERCOUNT; i++)
        {
            num[i] = (float)(rand() % 9 + 1);
            printf(" %d", (int)num[i]);
        }

        if (c == 'a')
        {
            char ans[32] = "null";
            printf("\n请输入你的答案（除最后一步外，每一个步骤均用括号包围，输入0代表无解）:\n");
            scanf("%s", ans);
            getchar();
            printf("正确答案可以为:\n");
            int ret = autoanswer(num);
            printf("共计 %d 条:\n", ret);
            bool correct = false;
            if (!isHit && ans[0] == '0')
            {
                correct = true;
            }
            else
            {
                for (int i = 0; i < 100; i++)
                {
                    char firstchar = *(ExpressPool + i * 32);
                    if (firstchar != '\0')
                    {

                        char* str1 = (char*)(ExpressPool + i * 32);

                        int cmpresult = strcmp(ExpressPool + i * 32, ans);
                        if (cmpresult == 0)
                        {
                            correct = true;
                        }
                    }
                }
            }
            free(ExpressPool);
            if (!correct)
            {
                printf("\n很遗憾，答错了~！\n");
            }
            else
            {
                printf("\n恭喜你，答对了~！\n");
            }
        }
        if (c == '\n')
        {
            printf("\n不尝试自己做一做么？回车看答案！\n");
            getchar();
            printf("答案可以为:\n");
            int ret = autoanswer(num);
            printf("共计 %d 条:\n", ret);
            free(ExpressPool);
        }
        if (c == 'm')
        {
            m_mode = true;
            for (int n1 = 1; n1 < 10; n1++)
                for (int n2 = 1; n2 < 10; n2++)

                    for (int n3 = 1; n3 < 10; n3++)
                        for (int n4 = 1; n4 < 10; n4++)
                        {

                            num[0] = (float)n1;
                            num[1] = (float)n2;
                            num[2] = (float)n3;
                            num[3] = (float)n4;
                            int ret = autoanswer(num);

                            printf("======================\n%d %d %d %d\n", n1, n2, n3, n4);
                            printf("%s = %d\n", ExpressPool, (int)RESULT);


                            free(ExpressPool);
                        }
        }
        printf("\n[enter]=随机计算;a=用户答题;q=退出\n");
        printf("请输入命令：");

        c = getchar();
    }
    printf("再见~！");
    return 0;
}