题解 | The Biggest Water Problem

#include <stdio.h>
int getNumer(int n){
    while(n>9){
        n=n%10+n/10;
        if(n>=0&&n<=9){
            break;
        }
    }    return n;
}
int main() {
    int n=0;
    scanf("%d",&n);
    printf("%d",getNumer(n));
    return 0;
}