1813167_ac_843ms_36k.c

北大大牛代码 1240道题的原代码 超级权威

# include <stdio.h>
# include <math.h>

long f(int m,int n)
{
 if(n == 0) return m;
 if(n == 1) return (m*(m+1)/2);
 if(m == n) return (long)(pow(2,n)-1);
 return (f(m-1,n-1) + 1 +f(m-1,n));
}
void main()
{
  int m, n, i;
  i = 0;
  while(1)
  {
  scanf("%d %d",&m,&n);
  if(m == 0 && n == 0) break;
  if(n>m) n=m;
  printf("Case %d: %ld\n",++i,f(m,n));
  }
}