Dada una array NxM de enteros que contienen elementos duplicados. La tarea es encontrar la suma de todos los elementos impares en la array dada. Esa es la suma de todos esos elementos cuya frecuencia es impar en la array.
Ejemplos :
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
Enfoque :
- Atraviese la array y use un mapa en C++ para almacenar la frecuencia de los elementos de la array de modo que la clave del mapa sea el elemento de la array y el valor sea su frecuencia en la array.
- Luego, recorra el mapa para encontrar la frecuencia de los elementos y verifique si es impar, si es impar, luego agregue este elemento por su frecuencia para sumar.
A continuación se muestra la implementación del enfoque anterior:
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>
Producción:
14
Tiempo Complejidad : O(N x M)
Espacio Auxiliar : O(N x M)