void sort(int *a, int n)

{
    if (n <= 1) {
        return;
    }

    int max_value = a[0];

    for (int i = 1; i < n; ++i) {
        if (a[i] > max_value) {
            max_value = a[i];
        }
    }

    int output[1000];
    int count[10];

    for (int exponent = 1; max_value / exponent > 0; exponent *= 10) {

        for (int digit = 0; digit < 10; ++digit) {
            count[digit] = 0;
        }

        for (int i = 0; i < n; ++i) {
            int digit = (a[i] / exponent) % 10;

            ++count[digit];
        }

        for (int digit = 1; digit < 10; ++digit) {
            count[digit] += count[digit - 1];
        }

        for (int i = n - 1; i >= 0; --i) {
            int digit = (a[i] / exponent) % 10;

            --count[digit];
            output[count[digit]] = a[i];
        }

        for (int i = 0; i < n; ++i) {
            a[i] = output[i];
        }
    }
}