int* countingSort(int arr_count, int* arr, int* result_count) {
    static int res_map[100] = {0};
    *result_count = 0;
    for (int i = 0; i<arr_count; i++){
        res_map[arr[i]] ++;
    }
    for (int i = 0; i<100; i++){
        if (res_map[i] != 0){
            for (int j = 0; j<res_map[i]; j++){
                arr[(*result_count)] = i;
                (*result_count)++;
            }
        }
    }
    return arr;
}