Find the first non-repeated character in a string

Question

I read of a job interview question to write some code for the following:

Write an efficient function to find the first nonrepeated character in a st

Answer 1

In Java, 1)Create the Character count hashmap. For each character,if there is no value stored in the character,set it to 1. Else increment the value of the character by 1 .

2)Then I Scanned the String for each character. Return character if the count in hashmap is 1 . If no character has count 1 ,then return null.

package com.abc.ridhi;
import java.util.HashMap;
import java.util.Scanner;

public class FirstNonRepeated {

    public static void main(String[] args) {
        System.out.println(" Please enter the input string :");
        Scanner in = new Scanner(System.in);
        String s = in.nextLine();
        char c = firstNonRepeatedCharacter(s);
        System.out.println("The first non repeated character is :  " + c);
    }

    public static Character firstNonRepeatedCharacter(String str) {
    HashMap map1 = new HashMap();
        int i, length;
        Character c;
        length = str.length(); 
        // Scan string and build hashmap
        for (i = 0; i < length; i++) {
            c = str.charAt(i);
            if (map1.containsKey(c)) {
                // increment count corresponding to c
                map1.put(c, map1.get(c) + 1);
            } else {
                map1.put(c, 1);
            }
        }
        // Search map in order of string str

        for (i = 0; i < length; i++) {
            c = str.charAt(i);
            if (map1.get(c) == 1){
                return c;
        }
        }
        return null;
    }
}