Example: Find the Number Occurring Odd Number of Times in C++

C
C++
C#
Java
Python
PHP
// Find the Number Occurring Odd Number of Times in C++
#include <bits/stdc++.h>
using namespace std;

// This function will find the odd number frequencies
int findSum(int arru[], int N) {
    unordered_map<int, int> mp;
    for (int i = 0; i < N; i++)
        mp[arru[i]]++;

    int sum = 0;

    // It will loop to iterate through map 
    for (auto itr = mp.begin(); itr != mp.end(); itr++) {
        if (itr->second % 2 != 0)
            sum += (itr->first) *(itr->second);
    }
    return sum;
}

int main() {
    // It will reserve array elements
    int arru[] = {10, 20, 20, 10, 40, 10, 40, 10, 20};

    // It will count size of the array
    int N = sizeof(arru) / sizeof(arru[0]);

    cout << "The sum of odd frequencies numbers: " << findSum(arru, N) << "\n";
    return 0;
}