int* shaker_sort(int* mas, int len){

    int right_index = (len - 1);
    int left_index = 0;

    int buf_1;
    int buf_2;


    while (left_index < right_index){
        for (int idx = left_index; idx < right_index; idx++){
            if (mas[idx+1] < mas[idx]){
                buf_1 = mas[idx];
                mas[idx] = mas[idx+1];
                mas[idx+1] = buf_1;
            }
        }
        right_index--;


        for (int idx = right_index; idx > left_index; idx--){
            if (mas[idx-1] > mas[idx]){
                buf_2 = mas[idx];
                mas[idx] = mas[idx-1];
                mas[idx-1] = buf_2;
            }
        }
        left_index++;
    }
    return mas;
}