# Sum of all maximum frequency elements in Matrix

Given a NxM matrix of integers containing duplicate elements. The task is to find the sum of all maximum occurring elements in the given matrix. That is the sum of all such elements whose frequency is even in the matrix.

Examples:

```Input : mat[] = {{1, 1, 1},
{2, 3, 3},
{4, 5, 3}}
Output : 12
The max occurring elements are 3 and 1
Therefore, sum = 1 + 1 + 1 + 3 + 3 + 3 = 12

Input : mat[] = {{10, 20},
{40, 40}}
Output : 80
```

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

Approach:

• Traverse the matrix and use a hash table to store the frequencies of elements of the matrix such that the key of map is the matrix element and value is its frequency in the matrix.
• Then traverse the map to find the maximum frequency.
• Finally, traverse the hash table to find the frequency of elements and check if it matches with the maximum frequency obtained in previous step, if yes, then add this element it’s frequency times to sum.

Below is the implementation of the above approach:

## C++

 `// C++ program to find sum of all max ` `// frequency elements in a Matrix ` ` `  `#include ` `using` `namespace` `std; ` ` `  `#define N 3 // Rows ` `#define M 3 // Columns ` ` `  `// Function to find sum of all max ` `// frequency elements in a Matrix ` `int` `sumMaxOccurring(``int` `arr[N][M]) ` `{ ` `    ``// Store frequencies of elements ` `    ``// in matrix ` `    ``unordered_map<``int``, ``int``> mp; ` `    ``for` `(``int` `i = 0; i < N; i++) { ` `        ``for` `(``int` `j = 0; j < M; j++) { ` `            ``mp[arr[i][j]]++; ` `        ``} ` `    ``} ` ` `  `    ``// loop to iterate through map ` `    ``// and find the maximum frequency ` `    ``int` `sum = 0; ` `    ``int` `maxFreq = INT_MIN; ` `    ``for` `(``auto` `itr = mp.begin(); itr != mp.end(); itr++) { ` `        ``if` `(itr->second > maxFreq) ` `            ``maxFreq = itr->second; ` `    ``} ` ` `  `    ``// Sum of maximum frequency elements ` `    ``for` `(``auto` `itr = mp.begin(); itr != mp.end(); itr++) {         ` `        ``if` `(itr->second == maxFreq) { ` `            ``sum += (itr->first) * (itr->second); ` `        ``} ` `    ``} ` ` `  `    ``return` `sum; ` `} ` ` `  `// Driver Code ` `int` `main() ` `{ ` `    ``int` `mat[N][M] = { { 1, 2, 3 }, ` `                      ``{ 1, 3, 2 }, ` `                      ``{ 1, 5, 6 } }; ` ` `  `    ``cout << sumMaxOccurring(mat) << endl; ` ` `  `    ``return` `0; ` `} `

## Java

 `// Java program to find sum of all max  ` `// frequency elements in a Matrix  ` `import` `java.util.*; ` ` `  `class` `GFG ` `{ ` ` `  `    ``static` `int` `N = ``3``; ``// Rows  ` `    ``static` `int` `M = ``3``; ``// Columns  ` ` `  `    ``// Function to find sum of all max  ` `    ``// frequency elements in a Matrix  ` `    ``static` `int` `sumMaxOccurring(``int` `arr[][]) ` `    ``{ ` `        ``// Store frequencies of elements  ` `        ``// in matrix  ` `        ``Map mp = ``new` `HashMap<>(); ` `        ``for` `(``int` `i = ``0``; i < N; i++)  ` `        ``{ ` `            ``for` `(``int` `j = ``0``; j < M; j++) ` `            ``{ ` `                ``if` `(mp.containsKey(arr[i][j]))  ` `                ``{ ` `                    ``mp.put(arr[i][j], mp.get(arr[i][j]) + ``1``); ` `                ``} ` `                ``else` `                ``{ ` `                    ``mp.put(arr[i][j], ``1``); ` `                ``} ` `            ``} ` `        ``} ` ` `  `        ``// loop to iterate through map  ` `        ``// and find the maximum frequency  ` `        ``int` `sum = ``0``; ` `        ``int` `maxFreq = Integer.MIN_VALUE; ` `        ``for` `(Map.Entry itr : mp.entrySet())  ` `        ``{ ` `            ``if` `(itr.getValue() > maxFreq) ` `            ``{ ` `                ``maxFreq = itr.getValue(); ` `            ``} ` `        ``} ` ` `  `        ``// Sum of maximum frequency elements  ` `        ``for` `(Map.Entry itr : mp.entrySet())  ` `        ``{ ` `            ``if` `(itr.getValue() == maxFreq) ` `            ``{ ` `                ``sum += (itr.getKey()) * (itr.getValue()); ` `            ``} ` `        ``} ` ` `  `        ``return` `sum; ` `    ``} ` ` `  `    ``// Driver Code  ` `    ``public` `static` `void` `main(String[] args)  ` `    ``{ ` `        ``int` `mat[][] = {{``1``, ``2``, ``3``}, ` `                        ``{``1``, ``3``, ``2``}, ` `                        ``{``1``, ``5``, ``6``}}; ` ` `  `        ``System.out.println(sumMaxOccurring(mat)); ` `    ``} ` `} ` ` `  `// This code is contributed by 29AjayKumar `

## Python3

 `# Python3 program to find sum of all max ` `# frequency elements in a Matrix ` `import` `sys ` ` `  `N ``=` `3` `# Rows ` `M ``=` `3` `# Columns ` ` `  `# Function to find sum of all max ` `# frequency elements in a Matrix ` `def` `sumMaxOccuring(arr): ` ` `  `    ``# Store frequencies of elements ` `    ``# in matrix ` `    ``mp ``=` `dict``() ` `    ``for` `i ``in` `range``(N): ` `        ``for` `j ``in` `range``(M): ` `            ``if` `arr[i][j] ``in` `mp: ` `                ``mp[arr[i][j]] ``+``=` `1` `            ``else``: ` `                ``mp[arr[i][j]] ``=` `1` ` `  `    ``# loop to iterate through map ` `    ``# and find the maximum frequency ` `    ``s ``=` `0` `    ``maxFreq ``=` `-``sys.maxsize ` `    ``for` `i ``in` `mp: ` `        ``if` `mp[i] > maxFreq: ` `            ``maxFreq ``=` `mp[i] ` ` `  `    ``# Sum of maximum frequency elements ` `    ``for` `i ``in` `mp: ` `        ``if` `mp[i] ``=``=` `maxFreq: ` `            ``s ``+``=` `i ``*` `mp[i] ` ` `  `    ``return` `s ` ` `  `# Driver code ` `if` `__name__ ``=``=` `"__main__"``: ` `    ``mat ``=` `[[``1``, ``2``, ``3``], ` `           ``[``1``, ``3``, ``2``], ` `           ``[``1``, ``5``, ``6``]] ` ` `  `    ``print``(sumMaxOccuring(mat)) ` ` `  `# This code is contributed by ` `# sanjeev2552 `

## C#

 `// C# program to find sum of all max  ` `// frequency elements in a Matrix  ` `using` `System; ` `using` `System.Collections.Generic;     ` `public` `class` `GFG ` `{ ` `  `  `    ``static` `int` `N = 3; ``// Rows  ` `    ``static` `int` `M = 3; ``// Columns  ` `  `  `    ``// Function to find sum of all max  ` `    ``// frequency elements in a Matrix  ` `    ``static` `int` `sumMaxOccurring(``int` `[,]arr) ` `    ``{ ` `        ``// Store frequencies of elements  ` `        ``// in matrix  ` `        ``Dictionary<``int``,``int``> mp = ``new` `Dictionary<``int``,``int``>(); ` `        ``for` `(``int` `i = 0; i < N; i++)  ` `        ``{ ` `            ``for` `(``int` `j = 0; j < M; j++) ` `            ``{ ` `                ``if` `(mp.ContainsKey(arr[i,j]))  ` `                ``{ ` `                    ``var` `v= mp[arr[i,j]]; ` `                    ``mp.Remove(arr[i,j]); ` `                    ``mp.Add(arr[i,j], v + 1); ` `                ``} ` `                ``else` `                ``{ ` `                    ``mp.Add(arr[i,j], 1); ` `                ``} ` `            ``} ` `        ``} ` `  `  `        ``// loop to iterate through map  ` `        ``// and find the maximum frequency  ` `        ``int` `sum = 0; ` `        ``int` `maxFreq = ``int``.MinValue; ` `        ``foreach``(KeyValuePair<``int``, ``int``> itr ``in` `mp) ` `        ``{ ` `            ``if` `(itr.Value > maxFreq) ` `            ``{ ` `                ``maxFreq = itr.Value; ` `            ``} ` `        ``} ` `  `  `        ``// Sum of maximum frequency elements  ` `        ``foreach``(KeyValuePair<``int``, ``int``> itr ``in` `mp) ` `        ``{ ` `            ``if` `(itr.Value == maxFreq) ` `            ``{ ` `                ``sum += (itr.Key) * (itr.Value); ` `            ``} ` `        ``} ` `  `  `        ``return` `sum; ` `    ``} ` `  `  `    ``// Driver Code  ` `    ``public` `static` `void` `Main(String[] args)  ` `    ``{ ` `        ``int` `[,]mat = {{1, 2, 3}, ` `                        ``{1, 3, 2}, ` `                        ``{1, 5, 6}}; ` `  `  `        ``Console.WriteLine(sumMaxOccurring(mat)); ` `    ``} ` `} ` `// This code contributed by Rajput-Ji `

Output:

```3
```

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