Duplicate Character Counter in Java

Welcome to the Duplicate Character Counter in Java page! Here, you'll find the source code for this program as well as a description of how the program works.

Current Solution

import java.util.*;

public class DuplicateCharacterCounter {
    public static void error() {
        System.out.println("Usage: please provide a string");
    }

    public static void main(String[] args) {
        if (args.length <= 0) {
            error();
        } else if (args[0].length() == 0) {
            error();
        } else {
            String inputStr = args[0];
            Map<Character, Integer> map = new HashMap<>();
            for (Character c : inputStr.toCharArray()) {
                map.put(c, map.getOrDefault(c, 0) + 1);
            }
            boolean flag = false;
            for (Character c : inputStr.toCharArray()) {
                if (map.get(c) > 1) {
                    flag = true;
                    System.out.printf("%c: %d\n", c, map.get(c));
                    map.put(c, 0);
                }
            }
            if (flag == false) {
                System.out.println("No duplicate characters");
            }
        }
    }
}

Duplicate Character Counter in Java was written by:

• Jeremy Grifski
• Vipin Yadav

If you see anything you'd like to change or update, please consider contributing.

How to Implement the Solution

No 'How to Implement the Solution' section available. Please consider contributing.

How to Run the Solution

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