C 语言程序设计实践 7.4 ackerman 函数

#include <stdio.h>
int ackerman (int m,int n);
int main()
{
int m,n;
scanf("%d %d",&m,&n);
printf("%d\n",ackerman(m,n));
return 0;
}

int ackerman (int m,int n)
{
if (m==0)
return n+1;
else if (m>0 && n==0)
return ackerman(m-1,1);
else
return ackerman(m-1,ackerman(m,n-1));
}