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# Replace duplicates with greater than previous duplicate value

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:

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 ``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 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

 ``

Output

`1 2 5 7 8 9 10 `

Time Complexity: O(N)
Auxiliary Space: O(N)