使用特别一点的递归解法：详细看代码

#include <iostream>
using namespace std;
int huan(int ping){
  if(ping == 1)
    return 0;
  else if(ping == 2 ){
    return 1;
  }else{
    return huan(2)+huan(ping - 2);
  }
}

int main(){
  int ping=0;
  while(cin>>ping){
    if (ping>1)
      cout<<huan(ping)<<endl;
  }
  return 0;
}