Skip to content
Related Articles

Related Articles

Improve Article

Replace duplicates with greater than previous duplicate value

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

Given an array of elements and change the array in such a way that all the elements on the array are distinct. If you are replacing a value, then the replacing value should be greater than the previous value and, after modification, the sum of the elements should be as small as possible.

Examples: 

Attention reader! Don’t stop learning now. Get hold of all the important DSA concepts with the DSA Self Paced Course at a student-friendly price and become industry ready.  To complete your preparation from learning a language to DS Algo and many more,  please refer Complete Interview Preparation Course.

In case you wish to attend live classes with experts, please refer DSA Live Classes for Working Professionals and Competitive Programming Live for Students.

Input : arr = {1, 2, 2, 5, 8, 8, 8} 
Output : 1 2 3 5 8 9 10 
8 is replaced with 9 (A non-existing element greater than 8). Next, duplicate occurrence of 8 is replaced with 10.



Input : arr = {1, 2, 5, 7, 8, 8, 7} 
Output : 1 2 5 7 8 9 10

Input : arr = {9, 9, 9, 9, 9} 
Output : 9 10 11 12 13 

Source: Paytm Interview Experience 30.

This problem is a variation of this article. In the above article, we had to replace the duplicates with the greatest value so far. But in this problem, we have to replace elements with duplicates greater than the previous duplicate value. 
The idea is to find the next greater element to be replaced to minimize the total sum. To find the next greater element, we have to iterate from the repeated element till the INT_MAX until the next greater element is found.

Below is the implementation of the above approach.  

C++




// CPP program to replace every repeating
// element with next greater element.
#include <bits/stdc++.h>
using namespace std;
 
void replaceElements(int arr[], int n)
{
    unordered_set<int> 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 {
 
            // find the next greatest element
            for (int j = arr[i] + 1; j < INT_MAX; j++) {
                if (s.find(j) == s.end()) {
                    arr[i] = j;
                    s.insert(j);
                    break;
                }
            }
        }
    }
}
 
int main()
{
    int arr[] = { 1, 2, 5, 7, 8, 8, 7 };
    int n = sizeof(arr) / sizeof(arr[0]);
 
    replaceElements(arr, n);
 
    for (int i = 0; i < n; i++)
        cout << arr[i] << " ";
    cout << "\n";
}

Java




// Java program to replace every repeating
// element with next greater element.
import java.util.HashSet;
import java.util.Set;
 
public class ReplaceDuplicateWithGreaterThanPreviousDuplicate {
 
    private static void replaceElements(int[] arr, int n)
    {
        Set<Integer> st = new HashSet<>();
        for (int i = 0; i < n; i++) {
            // check whether the element is
            // repeated or not
            if (!st.contains(arr[i])) {
                st.add(arr[i]);
            }
            else {
                // find the next greatest element
                for (int j = arr[i] + 1; j < Integer.MAX_VALUE; j++) {
                    if (!st.contains(j)) {
                        arr[i] = j;
                        st.add(j);
                        break;
                    }
                }
            }
        }
    }
    public static void main(String[] args)
    {
        int[] arr = new int[] { 1, 2, 5, 7, 8, 8, 7 };
        int n = arr.length;
        replaceElements(arr, n);
 
        for (int i = 0; i < n; i++) {
            System.out.print(arr[i] + " ");
        }
    }
}

Python3




# Python3 program to replace every repeating
# element with next greater element.
import sys
 
def replaceElements(arr, n):
 
    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 :
 
            # find the next greatest element
            for j in range(arr[i] + 1, sys.maxsize) :
                if j not in s:
                    arr[i] = j
                    s.append(j)
                    break
 
# Driver Code
if __name__ == "__main__":
 
    arr = [ 1, 2, 5, 7, 8, 8, 7 ]
    n = len(arr)
 
    replaceElements(arr, n)
 
    for i in range(n):
        print (arr[i], end = " ")
    print ()
 
# This code is contributed
# by ChitraNayal

C#




// C# program to replace every repeating
// element with next greater element.
using System;
using System.Collections.Generic;
 
public class ReplaceDuplicateWithGreaterThanPreviousDuplicate
{
    private static void replaceElements(int[] arr, int n)
    {
        HashSet<int> st = new HashSet<int>();
        for (int i = 0; i < n; i++)
        {
            // check whether the element is
            // repeated or not
            if (!st.Contains(arr[i]))
            {
                st.Add(arr[i]);
            }
            else
            {
                // find the next greatest element
                for (int j = arr[i] + 1; j < int.MaxValue; j++)
                {
                    if (!st.Contains(j))
                    {
                        arr[i] = j;
                        st.Add(j);
                        break;
                    }
                }
            }
        }
    }
     
    // Driver Code
    public static void Main(String[] args)
    {
        int[] arr = new int[] { 1, 2, 5, 7, 8, 8, 7 };
        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




<script>
// Javascript program to replace every repeating
// element with next greater element.
     
    function replaceElements(arr,n)
    {
        let st = new Set();
        for (let i = 0; i < n; i++) {
            // check whether the element is
            // repeated or not
            if (!st.has(arr[i])) {
                st.add(arr[i]);
            }
            else {
                // find the next greatest element
                for (let j = arr[i] + 1; j < Number.MAX_VALUE; j++) {
                    if (!st.has(j)) {
                        arr[i] = j;
                        st.add(j);
                        break;
                    }
                }
            }
        }
    }
     
    let arr=[1, 2, 5, 7, 8, 8, 7];
    let n = arr.length;
    replaceElements(arr, n);
   
    for (let i = 0; i < n; i++) {
        document.write(arr[i] + " ");
    }
     
       
 
 
// This code is contributed by avanitrachhadiya2155
</script>
Output: 
1 2 5 7 8 9 10

 




My Personal Notes arrow_drop_up
Recommended Articles
Page :