Repeating element GFG

 package com.company;

public class RepeatingElement {
//    EFFICIENT SOLUTION
    public static int getRepeatedElement(int[] arr) {
        int n = arr.length;
        boolean[] visited = new boolean[n];
        for(int i = 0; i< n; i++) {
            visited[i] = false;
        }
        for(int i = 0; i< n; i++) {
            if(visited[arr[i]]){
                return arr[i];
            }
            visited[arr[i]] = true;
        }
        return -1;
    }
// More efficient solution
    public static int get(int[] arr){
        int n = arr.length;
       int slow = arr[0] + 1;
       int fast = arr[0] + 1;
       do{
           slow = arr[slow] + 1;
           fast = arr[arr[fast] + 1] + 1;
       }while(slow != fast);

       slow = arr[0] + 1;
       while(slow != fast) {
           slow = arr[slow] + 1;
           fast = arr[fast] + 1;
       }
       return slow - 1;
    }
    public static void main(String[] args) {
         int[] array = {0,3,1,3,4,2};
        System.out.println(get(array));
    }
}