mirror of https://github.com/TheAlgorithms/C
96 lines
2.3 KiB
C
96 lines
2.3 KiB
C
// sorting of array list using Radix sort
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
|
|
#define range 10 // Range for integers is 10 as digits range from 0-9
|
|
|
|
// Utility function to get the maximum value in ar[]
|
|
int MAX(int *ar, int size)
|
|
{
|
|
int i, max = ar[0];
|
|
for (i = 0; i < size; i++)
|
|
{
|
|
if (ar[i] > max)
|
|
max = ar[i];
|
|
}
|
|
return max;
|
|
}
|
|
|
|
// Counting sort according to the digit represented by place
|
|
void countSort(int *arr, int n, int place)
|
|
{
|
|
int i, freq[range] = {0};
|
|
int *output = (int *)malloc(n * sizeof(int));
|
|
|
|
// Store count of occurrences in freq[]
|
|
for (i = 0; i < n; i++) freq[(arr[i] / place) % range]++;
|
|
|
|
// Change freq[i] so that it contains the actual position of the digit in
|
|
// output[]
|
|
for (i = 1; i < range; i++) freq[i] += freq[i - 1];
|
|
|
|
// Build the output array
|
|
for (i = n - 1; i >= 0; i--)
|
|
{
|
|
output[freq[(arr[i] / place) % range] - 1] = arr[i];
|
|
freq[(arr[i] / place) % range]--;
|
|
}
|
|
|
|
// Copy the output array to arr[], so it contains numbers according to the
|
|
// current digit
|
|
for (i = 0; i < n; i++) arr[i] = output[i];
|
|
free(output);
|
|
}
|
|
|
|
/*This is where the sorting of the array takes place
|
|
arr[] --- Array to be sorted
|
|
n --- Array Size
|
|
max --- Maximum element in Array
|
|
*/
|
|
void radixsort2(int *arr, int n,
|
|
int max) // max is the maximum element in the array
|
|
{
|
|
int mul = 1;
|
|
while (max)
|
|
{
|
|
countSort(arr, n, mul);
|
|
mul *= 10;
|
|
max /= 10;
|
|
}
|
|
}
|
|
|
|
void display(int *arr, int N)
|
|
{
|
|
for (int i = 0; i < N; i++) printf("%d, ", arr[i]);
|
|
putchar('\n');
|
|
}
|
|
|
|
int main(int argc, const char *argv[])
|
|
{
|
|
int n;
|
|
printf("Enter size of array:\n");
|
|
scanf("%d", &n); // E.g. 8
|
|
|
|
printf("Enter the elements of the array\n");
|
|
int i;
|
|
int *arr = (int *)malloc(n * sizeof(int));
|
|
for (i = 0; i < n; i++)
|
|
{
|
|
scanf("%d", &arr[i]);
|
|
}
|
|
|
|
printf("Original array: ");
|
|
display(arr, n); // Original array : 10 11 9 8 4 7 3 8
|
|
|
|
int max;
|
|
max = MAX(arr, n);
|
|
|
|
radixsort2(arr, n, max);
|
|
|
|
printf("Sorted array: ");
|
|
display(arr, n); // Sorted array : 3 4 7 8 8 9 10 11
|
|
|
|
free(arr);
|
|
return 0;
|
|
}
|