`` 挑战最短代码

#include<bits/stdc++.h>
using namespace std;
int main()
{
    int n;
    cin >> n;
    cout << n + n / 1000 + n / 100 % 10 + n / 10 % 10 + n % 10;
    return 0;
}

#include <bits/stdc++.h>
using namespace std;
int main()
{
	int n;
	cin >> n;
	int a = n / 1000;
	int b = n / 100 % 10;
	int c = n / 10 % 10;
	int d = n % 10;
	cout << n + a + b + c + d;
    return 0;
}

#include<bits/stdc++.h>
using namespace std;
int main()
{
    int n;
	cin >> n;
	int a=n/1000;
	int b=n/100%10;
	int c=n/10%10;
	int d=n%10;
    n = n + a + b + c + d;
	cout << n;
    return 0;
}

A

过辣！（脑残人士的欢呼）

    long long n,sum=0;
    cin>>n;
    sum+=n;
    sum+=n/1000;//千
    sum+=n%10;//个
    n/=10;
    sum+=n%10;//十
    n/=10;
    sum+=n%10;
    cout<<sum;

#include <iostream>//hetao3097453
using namespace std;
int main()
{
    int n1;
    cin >> n1;
    int a = n1 % 10;
    int b = n1 / 10 % 10;
    int c = n1 / 100 % 10;
    int d = n1 / 1000;
    int n2 = a + b + c + d;
    cout << n1 + n2 << endl;
    return 0;
}