pku1942

&l

 Source Code

Problem: 1942		User: henry11
Memory: 156K		Time: 0MS
Language: C		Result: Accepted

• Source Code

• #include<stdio.h>
  
  long long Count(long long a, long long b)
  {
      if(b>0)
      {
          return Count(a-1, b-1)*a/b;
      }    
      else
      {
          return 1;
      }    
  }    
  
  int main()
  {
      long long n, m;
      while(scanf("%I64d%I64d",t;/span> &n, &m) != EOF && (n||m))
      {
          printf("%I64d/n", Count(n+m, n>m ? m : n));
      }    
      return 1;
  }    

一直想不通，（m+n）!/m!n! 这个是怎么来的，排列组合还要复习下才好。