计算组合数

Bertha 。 2022-11-14 13:23 170阅读 0赞

#include<stdio.h>
    /* 函数原型 */
    long Fact(int x);
    long Comb(int m, int k);
    /* 计算 n的阶乘n! */
    long Fact(int n)
    {
        if(n == 0 || n == 1)
        {
            return 1;
        }
        else
        {
            return n * Fact(n - 1);
        }
    }
    /* 计算组合数 */
    long Comb(int m, int k)
    {
        return Fact(m) / (Fact(k) * Fact(m - k));
    }
    /* */
    int main()
    {
        /* 组合数下标 */
        int m;
        /* 组合数上标 */
        int n;
        /* */
        printf("Input m and n, and please ensure that m >= n:\n");
        /* 确保在非法输入下程序还能回归正轨 */
        while(scanf("m=%d, n=%d", &m, &n) != 2)
        {
            while(getchar() != '\n') ;
            printf("Input m and n, and please ensure that m >= n:\n");
        }
        /* 判断数据的合法性 */
        if(m >= n && m > 0 && n >= 0)
        {
            /* 输入数据合法 */
            printf("C(%d ,%d) = %ld.\n", m, n, Comb(m, n));
        }
        else
        {
            /* 输入数据非法 */
            printf("data error!\n");
        }
        /* */
        return 0;
    }

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjA0ODQ2Mw_size_16_color_FFFFFF_t_70][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjA0ODQ2Mw_size_16_color_FFFFFF_t_70 1][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjA0ODQ2Mw_size_16_color_FFFFFF_t_70 2][]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjA0ODQ2Mw_size_16_color_FFFFFF_t_70]: /images/20221022/f36bc9fcbbca4d6183d682ab68faec9d.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjA0ODQ2Mw_size_16_color_FFFFFF_t_70 1]: /images/20221022/b99a9679c76044fca470fa821ee545c1.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjA0ODQ2Mw_size_16_color_FFFFFF_t_70 2]: /images/20221022/49f36dac378a4ad0ab07f66333bdaad6.png