duplicatearr.cpp

#include <iostream>
using namespace std;

void findDuplicates(int arr[], int size) {
    // Assuming the numbers are in the range [-1000, 1000]
    const int range = 2001;  // Range from -1000 to 1000
    int offset = 1000;       // To handle negative numbers by shifting them to positive indexes

    // Dynamically allocate memory for the hash map (frequency array)
    int* freqMap = new int[range]();  // Initialize all values to 0

    cout << "Duplicates found: ";
    bool foundDuplicate = false;
    
    // Traverse the array and count the frequency of each element
    for (int i = 0; i < size; ++i) {
        int index = arr[i] + offset;  // Shifting element to a valid index
        freqMap[index]++;

        // If the frequency is greater than 1, it's a duplicate
        if (freqMap[index] == 2) {
            cout << arr[i] << " ";
            foundDuplicate = true;
        }
    }

    // If no duplicates were found
    if (!foundDuplicate) {
        cout << "No duplicates found.";
    }

    delete[] freqMap;  // Free the dynamically allocated memory
}

int main() {
    int arr[] = {4, 3, 6, 7, 4, 8, 3, 2, 5};  // Example input
    int size = sizeof(arr) / sizeof(arr[0]);

    findDuplicates(arr, size);
    cout << endl;

    return 0;
}