1810589_re.c

北大大牛代码 1240道题的原代码 超级权威

# include <stdio.h>

long f(int n)
{
 int i; long sum;
 sum = 0;
 if(n==0) return 1;
 for(i = 0; i < n; i+=2)
	 sum += 2*f(i);
 return sum + f(n-2);
}
void main()
{
 int n;
while(1)
 {
  scanf("%d",&n);
  if(n==-1) break; 
  printf("%ld\n",f(n));
 }
}