Given a NxM matrix of integers containing duplicate elements. The task is to find the sum of all odd occurring elements in the given matrix. That is the sum of all such elements whose frequency is odd in the matrix.
Examples:
Input : mat[] = {{1, 1, 2}, {2, 3, 3}, {4, 5, 3}} Output : 18 The odd occurring elements are 3, 4, 5 and their number of occurrences are 3, 1, 1 respectively. Therefore, sum = 3+3+3+4+5 = 18. Input : mat[] = {{10, 20}, {40, 40}} Output : 30
Approach:
- Traverse the matrix and use a map in C++ to store the frequency 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 frequency of elements and check if it is odd, if it is odd, 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 odd // 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 odd // frequency elements in a Matrix int sumOddOccurring( int arr[N][M])
{ // Store frequencies of elements
// in matrix
map< int , int > mp;
for ( int i = 0; i < N; i++) {
for ( int j = 0; j < M; j++) {
mp[arr[i][j]]++;
}
}
// Sum of odd frequency elements
int sum = 0;
for ( auto itr = mp.begin(); itr != mp.end(); itr++) {
if (itr->second % 2 != 0) {
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 << sumOddOccurring(mat) << endl;
return 0;
} |
Java
// Java program to find sum of all odd // 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 odd
// frequency elements in a Matrix
static int sumOddOccurring( 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 );
}
}
}
int sum = 0 ;
// Sum of odd frequency elements
for (Map.Entry<Integer, Integer> itr : mp.entrySet())
{
if (itr.getValue() % 2 != 0 )
{
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(sumOddOccurring(mat));
}
} // This code is contributed by 29AjayKumar |
Python3
# Python3 program to find sum of all odd # frequency elements in a Matrix # Function to find sum of all odd # frequency elements in a Matrix def sumOddOccurring(mat):
# Store frequencies of elements
# in matrix
mp = {}
n, m = len (mat), len (mat[ 0 ])
for i in range (n):
for j in range (m):
if mat[i][j] in mp:
mp[(mat[i][j])] = mp.get(mat[i][j]) + 1
else :
mp[(mat[i][j])] = 1
# Sum of odd frequency elements
_sum = 0
for i in range (n):
for j in range (m):
if mp.get(mat[i][j]) % 2 = = 1 :
_sum + = mat[i][j]
return _sum
# Driver Code if __name__ = = '__main__' :
mat = [[ 1 , 2 , 3 ],[ 1 , 3 , 2 ],[ 1 , 5 , 6 ]]
print (sumOddOccurring(mat))
# This code is Contributed by Vikash Kumar 37 |
C#
// C# program to find sum of all odd // frequency elements in a Matrix using System;
using System.Collections.Generic;
class GFG
{ static int N = 3; // Rows
static int M = 3; // Columns
// Function to find sum of all odd
// frequency elements in a Matrix
static int sumOddOccurring( 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);
}
else
{
mp.Add(arr[i,j], 1);
}
}
}
int sum = 0;
// Sum of odd frequency elements
foreach (KeyValuePair< int , int > itr in mp)
{
if (itr.Value % 2 != 0)
{
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(sumOddOccurring(mat));
}
} // This code is contributed by Princi Singh |
Javascript
<script> // JavaScript program to find sum of all odd // frequency elements in a Matrix var N = 3; // Rows
var M = 3; // Columns
// Function to find sum of all odd // frequency elements in a Matrix function sumOddOccurring(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);
}
else
{
mp.set(arr[i][j], 1);
}
}
}
var sum = 0;
// Sum of odd frequency elements
mp.forEach((value, key) => {
if (value % 2 != 0)
{
sum += (key) * (value);
}
});
return sum;
} // Driver Code var mat = [[1, 2, 3],
[1, 3, 2], [1, 5, 6]]; document.write(sumOddOccurring(mat)); </script> |
Output
14
Complexity Analysis:
- Time Complexity: O(N x M)
- Auxiliary complexity: O(N x M)