FirstNonRepetiveElement

package Udemyprograms;

import java.util.HashMap;
import java.util.Map;

public class Arrays19GeeksForGeeks {

  public static void FirstNonRepetiveElemet(int[] arr) {
    /**
    * Declare a HashMap 
    * iterate a loop
    * check if the array element is present in the map 
    * if no Insert the array element in the hashmap with value as 1
    * if yes increment the value of the key
    * After iteration over
    * iterate through map
    * if the value of the mkey is one 
    * return key
    * 
    */
    HashMap<Integer, Integer> map = new HashMap<>();
    for (int i = 0; i < arr.length; i++) {
      if (map.containsKey(arr[i])) {
        map.put(arr[i], map.get(arr[i]) + 1);
      } else {
        map.put(arr[i], 1);
      }
    }

    for (Map.Entry<Integer, Integer> mapValue : map.entrySet()) {
      if (mapValue.getValue() == 1) {
        System.out.println(mapValue.getKey());
        break;
      }
    }

  }

  public static void main(String args[]) {
    int[] arr = {9, 4, 9, 6, 7, 4};
    FirstNonRepetiveElemet(arr);

  }
}