【CCF】——Sum of Digits

Problem description
　　Given a decimal integer n, output the sum of the digits of n.
Input format
　　Input an integer n.
Output format
　　outputs an integer to indicate the answer.
Sample input

20151220

Sample output

13

The example shows that the
　　sum of the digits of 20151220 is 2+0+1+5+1+2+2+0=13.
Evaluation use case scale and conventions
　　All evaluation use cases meet: 0 ≤ n ≤ 1000000000.

By evaluating the scale and regulations of the use case, it can be seen that n does not exceed the range of integer, just store it directly in integer

#include <iostream>
using namespace std;

int main(){
    
    
	ios::sync_with_stdio(false);
	int n,sum = 0;
	cin >> n;
	while(n!=0){
    
    
		sum += n%10;
		n /= 10;
	}
	cout << sum;
	return 0;
}