radix.c

#include <stdio.h>
#include <string.h>

#define MAX 256
#define INT_BITS 32

void countingSort(int arr[], int n, int exp) {
    int output[n]; // output array
    int i, count[MAX] = {0};

    for (i = 0; i < n; i++)
        count[(arr[i] >> exp) & (MAX - 1)]++;

    for (i = 1; i < MAX; i++)
        count[i] += count[i - 1];

    for (i = n - 1; i >= 0; i--) {
        output[count[(arr[i] >> exp) & (MAX - 1)] - 1] = arr[i];
        count[(arr[i] >> exp) & (MAX - 1)]--;
    }

    for (i = 0; i < n; i++)
        arr[i] = output[i];
}

void radixsort(int arr[], int n) {
    for (int exp = 0; exp < INT_BITS; exp += 8)
        countingSort(arr, n, exp);
}

void printArray(int arr[], int n) {
    for (int i = 0; i < n; i++)
        printf("%d ", arr[i]);
    printf("\n");
}

int main() {
    int arr[] = {170, 45, 75, 90, 802, 24, 2, 66};
    int n = sizeof(arr)/sizeof(arr[0]);
    radixsort(arr, n);
    printArray(arr, n);
    return 0;
}
# https://chat.openai.com/share/06e83721-73ed-4174-a0fb-c385ff7396d0