漫遊於歷史與現代之間

Visual Basic

Module Module1
    Function pro(ByVal x As Integer) As Integer
        Dim i, y As Integer
        y = 1
        For i = 1 To x
            y = y * i
        Next
        pro = y
    End Function

    Sub Main()
        Dim m, n, a As Integer
        m = Console.ReadLine()
        n = Console.ReadLine()
        a = pro(m) / (pro(m - n) * pro(n))
        Console.Write(a)
        Console.ReadKey()
    End Sub

End Module

C language

#include<stdio.h>
    int function(int x);
    
    void main(void)
    {
     int c,x,y,z;
     printf("Enter m：\n");
     scanf("%d", &x);
     printf("Enter m：\n");
     scanf("%d", &y);
     z=function(x-y);
     x=function(x);
     y=function(y);
     c = x / (y * z);
     printf("C=%d",c);
     getch();   
    }
    
   int function(int x)
    {
     int i,p;
     p=1;
     for(i=1;i<=x;i++)
     {
      p=i*p;             
     }     
     return p;
    }

本程式為m個相異物品中，任意不重複取出n個，不計前後次序的組合方法。即C(m取n)=m!/(m-n)!*n!。