Problem:
Score : 200 points

Problem Statement

You are given a string S consisting of lowercase English letters. Determine whether all the characters in S are different.

Constraints

2 ≤ |S| ≤ 26, where |S| denotes the length of S.

S consists of lowercase English letters.

Input

Input is given from Standard Input in the following format:

S

Output

If all the characters in S are different, print yes (case-sensitive); otherwise, print no.

Sample Input 1

uncopyrightable

Sample Output 1

yes

Sample Input 2

different

Sample Output 2

no

Sample Input 3

no

Sample Output 3

yes

Solution in C++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <iostream>
#include <fstream>
#include <string>
#include<cmath>
#include<queue>

using namespace std;

int main()
{

    char a[30];
    string s;
    int count = 0;
    int i,j,n;

    cin >> s;
    n = s.length();
    cout << n<<endl;

    for (i = 0 ; i <= n ; i++)
    {
        a[i]=s[i];
    }
    for (i = 0 ; i <= n-1 ; i++)
    {
        for (j = i + 1 ; j <= n+1 ; j++)
        {
            if (a[i] == a[j])
            {
                count = count + 1;
            }
        }
    }
    if (count != 0)
        cout << "no" << endl;
    else
        cout << "yes" << endl;
};