编辑代码

#include <stdio.h>
void print(int x)           
{                           //x=123
    if(x>9)                 //123/10=x=12
    {                       //12/10=x=1
        print(x/10);        //从最后一层开始执行和打印
    }
    printf("%d\n",x%10);
}
int main () {
  int num;
  scanf("%d",&num);
  print(num);
    return 0;
}