#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
int main() {
int a, he = 0;
scanf("%d", &a);
//循环检验每个位数相加的和是否为个位数 是则跳出循环
for (int y = 0; y < 10; y++) {
for (int x = 0; x < 10; x++) {
he += a % 10;
a /= 10;
}
if (he / 10 == 0) {
break;
}
else
{
a = he; he = 0;
}
}
printf("%d", he);
return 0;
} #include <stdio.h>
//求数位之和
int sum(int i){
if (i > 0){
return (i%10) + sum(i/10);
}else{
return 0;
}
}
//检查是否是个位数
int check(int a){
while (a / 10 != 0){
a = sum(a);
}
return a;
}
int main() {
int a;
scanf("%d",&a);
int b = check(a);
printf("%d",b);
return 0;
}
//
// Created by Wilbur Lee on 10/7/2024.
//
#include <stdio.h>
//函数递归
int DigitSum(int n)
{
if(n <= 10)
return n % 10;
//算出位数之和
int sum = (n % 10)+DigitSum(n / 10);
//判断位数之和,大于10就重新进行一次位数之和
if(sum > 10)
return (sum % 10)+DigitSum(sum / 10);
//到这说明位数之和已经小于10了
return sum;
}
int main() {
int n;
scanf("%d", &n);
int count = DigitSum(n);
printf("%d", count);
return 0;
} #include <stdio.h>
int GetAllBitsNum(long long* n);
int main() {
long long n;
while (scanf("%lld", &n) != EOF) {
int sum = GetAllBitsNum(&n);
printf("%d\n", sum);
}
return 0;
}
int GetAllBitsNum(long long* n) {
int res;
long long tmp;
// 循环至少要执行一次
do {
// res值归0,重新开始计算
res = 0;
while (*n > 0) {
tmp = *n % 10;
res += tmp;
*n /= 10;
}
if (res >= 10) {
// 上述循环过后*n的值已为0,这里用res给*n重新赋值
*n = res;
}
} while (res >= 10);
return res;
}
#include <stdio.h>
void transform(int num);
int main() {
int num, result;
scanf("%d", &num);
transform(num);
return 0;
}
void transform(int num){
int digit, digit_sum = 0;
while (num) {
digit = num % 10;
digit_sum += digit;
num /= 10;
}
if(digit_sum > 9){
transform(digit_sum);
} else {
printf("%d", digit_sum);
}
} #define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>
int ss(int x) {
int s = 0;
int x1 = x;
while (x1) {
s += x1 % 10;
x1 /= 10;
}
if (s >= 10) {
ss(s);
}
else {
return s;
}
}
int main() {
int n;
scanf("%d", &n);
int a = ss(n);
printf("%d", a);
return 0;
}
#include<stdio.h>
int DaBianShen(int num) {
int sum = 0;
while (num) {
sum += num % 10;
num /= 10;
}
if (sum > 9)
return DaBianShen(sum);
else
return sum;
}
int main() {
int num = 0;
scanf("%d", &num);
printf("%d\n", DaBianShen(num));
return 0;
}