Java Program to Check Strings Anagram Using HashMap

// Java Program to Check if
// String are Anagram using
// HashMap
import java.io.*;
import java.util.*;

// Driver Class
class GFG {
    // main function
    public static boolean is_Anagram(String a, String b)
    {
        // Length of String Equal or not
        if (a.length() != b.length()) {
            return false;
        }

        // Create a HashMap
        HashMap<Character, Integer> map = new HashMap<>();

        // Using Loop to iterate String
        for (int i = 0; i < a.length(); i++) {

            if (map.containsKey(a.charAt(i))) {
                // If contains increase count by 1 for that
                // character
                map.put(a.charAt(i),
                        map.get(a.charAt(i)) + 1);
            }
            else {
                // first occurence of the element
                map.put(a.charAt(i), 1);
            }
        }

        // Now loop over String b
        for (int i = 0; i < b.length(); i++) {

            // Checking current character already
            // exists in HashMap
            if (map.containsKey(b.charAt(i))) {
                // Maintaing the count in map
                map.put(b.charAt(i),
                        map.get(b.charAt(i)) - 1);
            }
            else {
                return false;
            }
        }

        // Extract all keys of HashMap/map
        Set<Character> keys = map.keySet();

        // Checking if count of all the elements
        // are equal
        for (Character key : keys) {
            if (map.get(key) != 0) {
                return false;
            }
        }
        // Returning True as all keys are zero
        return true;
    }
    public static void main(String[] args)
    {
        String str1 = "gram";
        String str2 = "arm";

        // Function call
        if (is_Anagram(str1, str2))
            System.out.print("The two strings are "
                             + "anagram of each other");
        else
            System.out.print("The two strings are "
                             + "not anagram of each other");
    }
}