✅First non-repeating character in a String(Contest)

First non-repeating character in a String easy asked in interviews by 3 companies Time Limit: 2 sec Memory Limit: 128000 kB

Problem Statement :

Given a string s, find the first non-repeating character in the string and return its index. If it does not exist, return -1. Input First line of the input contains the string s.

Constraints 1<= s. length <= 100000 Output Print the index of the first non- repeating character in a string Example Input s = "newtonschool"

Output 1

Explanation "e" is the first non- repeating character in a string

link:https://my.newtonschool.co/playground/code/yg89y55pdh87

```java
import java.io.*; // for handling input/output
import java.util.*; // contains Collections framework

// don't change the name of this class
// you can add inner classes if needed
class Main {
    public static void main (String[] args) {
        Scanner sc=new Scanner(System.in);
        String non = sc.nextLine();
        Map<Character, Integer> m = new HashMap<Character , Integer>();
        for(int i=0;i<non.length(); i++){
            if(m.get(non.charAt(i))!=null){
                m.put(non.charAt(i),m.get(non.charAt(i))+1);
            }else{
                m.put(non.charAt(i),1);
            }
        }
        for(int i=0;i<non.length();i++){
            if(m.get(non.charAt(i))==1){
                System.out.println(i);
                break;
            } else{
                if(i==non.length()-1){
                    System.out.println("-1");
                }
            }

        }
        // Your code here
    }
}
```