Java Exercises: Find the index of the first unique character in a given string

Java Basic: Exercise-148 with Solution

Write a Java program to find the index of the first unique character in a given string, assume that there is at least one unique character in the string.

Pictorial Presentation:

Sample Solution:

Java Code:

import java.util.*;
public  class  Solution {
    public static void main(String[] args) {
		String s = "wresource";
		System.out.println("Original String: "+s);
        System.out.println("First unique character of the above: "+first_Uniq_Char(s));
    }

    public static int first_Uniq_Char(String s) {
         int[] freq = new int[256];
        for (char c : s.toCharArray()) {
            freq[c - 'a']++;
        }
        for (int i = 0; i < s.length(); i++) {
            if (freq[s.charAt(i) - 'a'] == 1) return i;
        }
        return -1;
	}
 }

Sample Output:

Original String: wresource
First unique character of the above: 0

Flowchart:

Java Code Editor:

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