Question

How to count all duplicate elements in int array using C++

Answer 1

#include <iostream>

using namespace std;

int main() {
    int arr[] = { 1, 1, 2, 3, 4, 4, 4, 5, 6, 6, 7, 7, 7, 7 };
    int duplicate[10] = {0};
    int len = sizeof(arr) / sizeof(arr[0]);
    
    for (int i = 0; i < len; i++) {
        for (int j = 0; j < len; j++) {
            if (arr[i] == arr[j]) {
                duplicate[arr[i]]++;
                break;
            }
        }
    }
    
    for (int i = 0; i < 10; i++) {
        if (duplicate[i] > 1)
            cout << i << " : " << duplicate[i] << endl; 
    }
    
    return 0;
}



/*
run:

1 : 2
4 : 3
6 : 2
7 : 4

*/

 

70+ SQL courses for beginners and professionals