题解 The Biggest Water Problem

#include <stdio.h>

int game_(int n)
{
    int count=0;
    while(n!=0)
    {
        count+=(n%10);
        n/=10;
    }//求各数位相加之和
    if(count>9)//判断是否为个位数
    {
        count=game_(count);//否，再次调用再来一次
        return count;//递归结束条件：count>9 即：结果为个位数，故得到count直接返回即可
    }
    else {
    return count;
    }//是，直接返回
}

int main()
{
    int n=0;
    scanf("%d",&n);
    printf("%d\n",game_(n));
    return 0;
}