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
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 <bits/stdc++.h>using namespace std;#define N 3 // Rows#define M 3 // Columns// Function to find sum of all max// frequency elements in a Matrixint 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 Codeint 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<Integer, Integer> 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<Integer, Integer> itr : mp.entrySet()) { if (itr.getValue() > maxFreq) { maxFreq = itr.getValue(); } } // Sum of maximum frequency elements for (Map.Entry<Integer, Integer> 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 Matriximport sysN = 3 # RowsM = 3 # Columns# Function to find sum of all max# frequency elements in a Matrixdef sumMaxOccurring(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 codeif __name__ == "__main__": mat = [[1, 2, 3], [1, 3, 2], [1, 5, 6]] print(sumMaxOccurring(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 |
Javascript
<script>// JavaScript program to find sum of all max // frequency elements in a Matrix var N = 3; // Rows var M = 3; // Columns // Function to find sum of all max // frequency elements in a Matrix function sumMaxOccurring(arr){ // Store frequencies of elements // in matrix var mp = new Map(); for (var i = 0; i < N; i++) { for (var j = 0; j < M; j++) { if (mp.has(arr[i][j])) { var v= mp.get(arr[i][j]); mp.delete(arr[i][j]); mp.set(arr[i][j], v + 1); } else { mp.set(arr[i][j], 1); } } } // loop to iterate through map // and find the maximum frequency var sum = 0; var maxFreq = -1000000000; mp.forEach((value, key) => { if (value > maxFreq) { maxFreq = value; } }); // Sum of maximum frequency elements mp.forEach((value, key) => { if (value == maxFreq) { sum += (key) * (value); } }); return sum;}// Driver Code var mat = [[1, 2, 3], [1, 3, 2], [1, 5, 6]];document.write(sumMaxOccurring(mat));</script> |
Output
3
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