# Maximum element in an array which is equal to its frequency

Given an array of integers arr[] of size N, the task is to find the maximum element in the array whose frequecny equals to it’s value

Examples:

Input: arr[] = {3, 2, 2, 3, 4, 3}
Output: 3
Frequency of element 2 is 2
Frequency of element 3 is 3
Frequency of element 4 is 1
2 and 3 are elements which have same frequency as it’s value and 3 is the maximum.

Input: arr[] = {1, 2, 3, 4, 5, 6}
Output: 1

## Recommended: Please try your approach on {IDE} first, before moving on to the solution.

Approach: Store the frequency of every element of the array using the map, and finally find out the maximum of those element whose frequency is equal to their value.

Below is the implementation of the above approach:

## CPP

 `// C++ program to find the maximum element  ` `// whose frequency equals to it’s value ` ` `  `#include ` `using` `namespace` `std; ` ` `  `// Function to find the maximum element  ` `// whose frequency equals to it’s value ` `int` `find_maxm(``int` `arr[], ``int` `n) ` `{ ` `    ``// Hash map for counting frquency ` `    ``map<``int``, ``int``> mpp; ` ` `  `    ``for` `(``int` `i = 0; i < n; i++) { ` `        ``// Counting freq of each element ` `        ``mpp[arr[i]] += 1; ` `    ``} ` ` `  `    ``int` `ans = 0; ` `    ``for` `(``auto` `x : mpp) ` `    ``{ ` `        ``int` `value = x.first; ` `        ``int` `freq = x.second; ` `         `  `        ``// Check if value equls to frequency ` `        ``// and it is the maximum element or not ` `        ``if` `(value == freq) { ` `            ``ans = max(ans, value); ` `        ``} ` `    ``} ` ` `  `    ``return` `ans; ` `} ` ` `  `// Driver code ` `int` `main() ` `{ ` `    ``int` `arr[] = { 3, 2, 2, 3, 4, 3 }; ` `     `  `    ``// Size of array ` `    ``int` `n = ``sizeof``(arr) / ``sizeof``(arr); ` `     `  `    ``// Function call ` `    ``cout << find_maxm(arr, n); ` ` `  `    ``return` `0; ` `} `

## Java

 `// Java program to find the maximum element  ` `// whose frequency equals to it’s value ` `import` `java.util.*; ` ` `  `class` `GFG{ ` `  `  `// Function to find the maximum element  ` `// whose frequency equals to it’s value ` `static` `int` `find_maxm(``int` `arr[], ``int` `n) ` `{ ` `    ``// Hash map for counting frquency ` `    ``HashMap mp = ``new` `HashMap(); ` `  `  `    ``for` `(``int` `i = ``0``; i < n; i++) { ` `         `  `        ``// Counting freq of each element ` `        ``if``(mp.containsKey(arr[i])){ ` `            ``mp.put(arr[i], mp.get(arr[i])+``1``); ` `        ``}``else``{ ` `            ``mp.put(arr[i], ``1``); ` `    ``} ` `    ``} ` `  `  `    ``int` `ans = ``0``; ` `    ``for` `(Map.Entry x : mp.entrySet()) ` `    ``{ ` `        ``int` `value = x.getKey(); ` `        ``int` `freq = x.getValue(); ` `          `  `        ``// Check if value equls to frequency ` `        ``// and it is the maximum element or not ` `        ``if` `(value == freq) { ` `            ``ans = Math.max(ans, value); ` `        ``} ` `    ``} ` `  `  `    ``return` `ans; ` `} ` `  `  `// Driver code ` `public` `static` `void` `main(String[] args) ` `{ ` `    ``int` `arr[] = { ``3``, ``2``, ``2``, ``3``, ``4``, ``3` `}; ` `      `  `    ``// Size of array ` `    ``int` `n = arr.length; ` `      `  `    ``// Function call ` `    ``System.out.print(find_maxm(arr, n)); ` `  `  `} ` `} ` ` `  `// This code is contributed by 29AjayKumar `

## Python3

 `# Python3 program to find the maximum element  ` `# whose frequency equals to it’s value  ` ` `  `# Function to find the maximum element  ` `# whose frequency equals to it’s value  ` `def` `find_maxm(arr, n) : ` ` `  `    ``# Hash map for counting frquency  ` `    ``mpp ``=` `{} ` ` `  `    ``for` `i ``in` `range``(``0``,n): ` `        ``# Counting freq of each element  ` `        ``if``(arr[i] ``in` `mpp): ` `            ``mpp.update( {arr[i] : mpp[arr[i]] ``+` `1``} ) ` `        ``else``: ` `            ``mpp[arr[i]] ``=` `1` ` `  `    ``ans ``=` `0` `    ``for` `value,freq ``in` `mpp.items(): ` `        ``# Check if value equls to frequency  ` `        ``# and it is the maximum element or not  ` `        ``if` `(value ``=``=` `freq): ` `            ``ans ``=` `max``(ans, value) ` ` `  `    ``return` `ans ` ` `  `# Driver code  ` `arr ``=` `[ ``3``, ``2``, ``2``, ``3``, ``4``, ``3` `] ` `     `  `# Size of array  ` `n ``=` `len``(arr) ` ` `  `# Function call  ` `print``(find_maxm(arr, n)) ` ` `  `# This code is contributed by Sanjit_Prasad `

## C#

 `// C# program to find the maximum element  ` `// whose frequency equals to it’s value ` `using` `System; ` `using` `System.Collections.Generic; ` ` `  `class` `GFG{ ` `   `  `// Function to find the maximum element  ` `// whose frequency equals to it’s value ` `static` `int` `find_maxm(``int` `[]arr, ``int` `n) ` `{ ` `    ``// Hash map for counting frquency ` `    ``Dictionary<``int``,``int``> mp = ``new` `Dictionary<``int``,``int``>(); ` `   `  `    ``for` `(``int` `i = 0; i < n; i++) { ` `          `  `        ``// Counting freq of each element ` `        ``if``(mp.ContainsKey(arr[i])){ ` `            ``mp[arr[i]] = mp[arr[i]]+1; ` `        ``}``else``{ ` `            ``mp.Add(arr[i], 1); ` `    ``} ` `    ``} ` `   `  `    ``int` `ans = 0; ` `    ``foreach` `(KeyValuePair<``int``,``int``> x ``in` `mp) ` `    ``{ ` `        ``int` `value = x.Key; ` `        ``int` `freq = x.Value; ` `           `  `        ``// Check if value equls to frequency ` `        ``// and it is the maximum element or not ` `        ``if` `(value == freq) { ` `            ``ans = Math.Max(ans, value); ` `        ``} ` `    ``} ` `   `  `    ``return` `ans; ` `} ` `   `  `// Driver code ` `public` `static` `void` `Main(String[] args) ` `{ ` `    ``int` `[]arr = { 3, 2, 2, 3, 4, 3 }; ` `       `  `    ``// Size of array ` `    ``int` `n = arr.Length; ` `       `  `    ``// Function call ` `    ``Console.Write(find_maxm(arr, n)); ` `} ` `} ` ` `  `// This code is contributed by Rajput-Ji `

Output:

```3
```

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