Radix Sort

#include <iostream>
#include <algorithm>
using namespace std;

int getMax(int arr[], int n) {
    int max = arr[0];
    for (int i = 1; i < n; i++) {
        if (arr[i] > max)
            max = arr[i];
    }
    return max;
}

void countSort(int arr[], int n, int exp) {
    int output[n];
    int count[10] = {0};
    
    // Store count of occurrences
    for (int i = 0; i < n; i++)
        count[(arr[i] / exp) % 10]++;
    
    // Change count to position
    for (int i = 1; i < 10; i++)
        count[i] += count[i - 1];
    
    // Build output array
    for (int i = n - 1; i >= 0; i--) {
        output[count[(arr[i] / exp) % 10] - 1] = arr[i];
        count[(arr[i] / exp) % 10]--;
    }
    
    // Copy output to original array
    for (int i = 0; i < n; i++)
        arr[i] = output[i];
}

void radixSort(int arr[], int n) {
    int max = getMax(arr, n);
    
    // Do counting sort for every digit
    for (int exp = 1; max / exp > 0; exp *= 10)
        countSort(arr, n, exp);
}

void printArray(int arr[], int n) {
    for (int i = 0; i < n; i++) {
        cout << arr[i] << " ";
    }
    cout << endl;
}

int main() {
    int arr[] = {170, 45, 75, 90, 802, 24, 2, 66};
    int n = sizeof(arr) / sizeof(arr[0]);
    
    cout << "Original array: ";
    printArray(arr, n);
    
    radixSort(arr, n);
    
    cout << "Sorted array: ";
    printArray(arr, n);
    
    return 0;
}