radix_sort.cpp

#include <stdio.h>

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

void countSort(int arr[], int n, int exp)
{
	int output[n];
	int i, count[10] = { 0 };

	for (i = 0; i < n; i++)
		count[(arr[i] / exp) % 10]++;

	for (i = 1; i < 10; i++)
		count[i] += count[i - 1];

	for (i = n - 1; i >= 0; i--) {
		output[count[(arr[i] / exp) % 10] - 1] = arr[i];
		count[(arr[i] / exp) % 10]--;
	}

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

void radixsort(int arr[], int n)
{
	int m = getMax(arr, n);
	for (int exp = 1; m / exp > 0; exp *= 10)
		countSort(arr, n, exp);
}

void print(int arr[], int n)
{
	printf("Sorted array element:\n");
	for (int i = 0; i < n; i++)
		printf("%d ", arr[i]);
}

int main()
{
	printf("enter the array size:\n");
	int n;
	scanf("%d",&n);
	int arr[n];
	printf("enter the array element:\n");
	for(int i=0;i<n;i++)
	{
		scanf("%d",&arr[i]);
	}
	int size = sizeof(arr) / sizeof(arr[0]);

	radixsort(arr, size);

	print(arr, n);
	return 0;
}