String Construction

Amanda has a string of lowercase letters that she wants to copy to a new string. She can perform the following operations with the given costs. She can perform them any number of times to construct a new string p:
1.Append a character to the end of the string p at a cost of the dollar.
2.Choose any substring of p and append it to the end of p at no charge.
Given n strings s[i], find and print the minimum cost of copying each s[i] to p[i] on a new line.

Example:

Input:  q=1, s="abab"
Output: 2

Approach

Java

import java.util.HashSet;

public class StringConstruction {
    public static void main(String[] args) {
        String str = "abc";
        int count = stringConstruction(str);
        System.out.println(count);
    }

    static int stringConstruction(String s) {
        HashSet<Character> set = new HashSet<Character>();
        for (int i = 0; i < s.length(); i++) {
            set.add(s.charAt(i));
        }
        return set.size();
    }
}

C++

#include <bits/stdc++.h>
using namespace std;

int stringConstruction(string s)
{
    int f[26] = {0}, cnt = 0;
    for (int i = 0; i < s.size(); i++)
    {
        if (f[s[i] - 'a'] == 0)
        {
            f[s[i] - 'a']++;
            cnt++;
        }
        else
            f[s[i] - 'a']++;
    }
    return cnt;
}

int main()
{

    int q = 1;

    string s = "abab";

    int result = stringConstruction(s);

    cout << result << "\n";

    return 0;
}