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# Replace repeating elements with greater that greatest values

• Difficulty Level : Medium
• Last Updated : 25 May, 2021

Given an integer array, if an integer is repeating then replace it with a number greater than that number that has not been inserted yet in the array.
Examples:

Input : arr = {1, 3, 4, 5, 3}
Output : 1 3 4 5 6
Here 3 is repeating so it is replaced with 6

Input : arr = {1, 3, 4, 4, 5, 3}
Output : 1 3 4 6 5 7

We need to replace repeating numbers with a number that does not appear in the array and is one greater than the largest present in the array.
Source: Paytm Interview Experience (Backend Developer).
Calculate the maximum element in the array and replace the repeated elements with the maxx+1 and update the maxx element as visited. In the implementation, basic concept of hashing is used.

## C++

 // CPP program to replace repeating elements// with greater than the greatest.#include using namespace std; void replaceElements(int arr[], int n){    // Maximum element in an array    int maxx = *max_element(arr, arr+n);     unordered_set s;     for (int i = 0; i < n; i++) {                  // check whether the element is        // repeated or not        if (s.find(arr[i]) == s.end())            s.insert(arr[i]);         else {             // update the repeated element with the            // maxx element            arr[i] = maxx + 1;             maxx++; // update the max             // mark the maximum element as visited            s.insert(maxx);        }    }} // Driver codeint main(){    int arr[] = { 1, 3, 4, 5, 3 };    int n = sizeof(arr)/sizeof(arr[0]);    replaceElements(arr, n);    for (int i = 0; i < n; i++)        cout << arr[i] << " ";    return 0;}

## Java

 // Java  program to replace repeating elements// with greater than the greatest.import java.util.*;class Solution{    //returns the maximum element    static int max_element(int arr[])    {        int max=arr[0];        for(int i=1;i s=new Vector();      for (int i = 0; i < n; i++) {                   // check whether the element is        // repeated or not        if (!s.contains(arr[i]))            s.add(arr[i]);          else {              // update the repeated element with the            // maxx element            arr[i] = maxx + 1;              maxx++; // update the max              // mark the maximum element as visited            s.add(maxx);        }    }} // Driver codepublic static void main(String args[]){    int arr[] = { 1, 3, 4, 5, 3 };    int n = arr.length;    replaceElements(arr, n);    for (int i = 0; i < n; i++)        System.out.print( arr[i] + " ");     }}//contributed by Arnab Kundu

## Python3

 # Python 3 program to replace repeating# elements with greater than the greatest. def replaceElements( arr, n):     # Maximum element in an array    maxx = max(arr)     s = []     for i in range (n) :                 # check whether the element is        # repeated or not        if arr[i] not in s:            s.append(arr[i])         else:             # update the repeated element            # with the maxx element            arr[i] = maxx + 1             maxx += 1 # update the max             # mark the maximum element            # as visited            s.append(maxx) # Driver codeif __name__ =="__main__":     arr = [ 1, 3, 4, 5, 3 ]    n = len(arr)    replaceElements(arr, n)    for i in range( n):        print (arr[i], end = " ") # This code is contributed by ita_c

## C#

 // C# program to replace repeating elements// with greater than the greatest.using System;using System.Collections.Generic; class GFG{    //returns the maximum element    static int max_element(int []arr)    {        int max = arr[0];        for(int i = 1; i < arr.Length; i++)        {            if(max < arr[i])            max = arr[i];        }        return max;    }     static void replaceElements(int []arr, int n){    // Maximum element in an array    int maxx = max_element(arr);     List s = new List();     for (int i = 0; i < n; i++)    {                     // check whether the element is        // repeated or not        if (!s.Contains(arr[i]))            s.Add(arr[i]);         else        {             // update the repeated element with the            // maxx element            arr[i] = maxx + 1;             maxx++; // update the max             // mark the maximum element as visited            s.Add(maxx);        }    }} // Driver codepublic static void Main(){    int []arr = { 1, 3, 4, 5, 3 };    int n = arr.Length;    replaceElements(arr, n);    for (int i = 0; i < n; i++)        Console.Write( arr[i] + " ");}} // This code is contributed by PrinciRaj1992

## Javascript


Output:
1 3 4 5 6

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