题解 | 大水题
大水题
https://www.nowcoder.com/practice/6b9770de551c426287252421742f6ebf
#include <stdio.h>
int count_num(long long num){
if(num < 10){
return num;
}
int sum = 0;
while(num > 0){
sum += num % 10;
num /= 10;
}
return count_num(sum);
}
int main(void) {
long long n;
scanf("%lld", &n);
int ans = count_num(n);
printf("%d", ans);
return 0;
}
