Stalin sort algorithm

stalin_sort.cpp

/* Stalin sort algorithm
 * @urbanij
 * g++ -std=c++98 stalin_sort.cpp -o stalin_sort
 */

#include <iostream>
#include <time.h>
#define N 30

void populate_array(int* arr, int n) {
    srand (time(NULL));
    for (int i=0; i<n; ++i) {
        arr[i] = rand() % 100;
    }
}

void print(int* arr, int n) {
    for (int i=0; i<n; ++i) {
        if (arr[i] == -1) break;
        std::cout << arr[i] << ' ';
    }
    std::cout << '\n';
}

void stalin_sort(int* sorted_arr, int* arr, int n) {
    int last_elem = arr[0];
    sorted_arr[0] = last_elem;
    int index_sorted_arr = 1; 
    for (int i=1; i<n; ++i) {
        if (arr[i] >= last_elem) {
            sorted_arr[index_sorted_arr++] = arr[i];
            last_elem = arr[i];
        }
    }
}

int main() {
    std::cout << "Stalin sort algorithm:\n\n\teach element that is not in the\n\tcorrect order is simply eliminated from the list.\n\n";
    int arr[N], sorted_arr[N];
    memset(sorted_arr, -1, sizeof sorted_arr);
    populate_array(arr, N);
    stalin_sort(sorted_arr, arr, N);
    print(arr, N);
    print(sorted_arr, N);
    return 0;
}