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102-counting_sort.c
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102-counting_sort.c
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#include "sort.h"
#include <stdlib.h>
/**
* counting_sort - sorts an array of integers in ascending order
* using the Counting sort algorithm
* @array: array of integers
* @size: size of array
*/
void counting_sort(int *array, size_t size)
{
int *count = NULL, *output = NULL;
int i = 0, max = 0;
if (!array || size < 2)
return;
max = array[0];
for (i = 1; i < (int)size; i++)
if (array[i] > max)
max = array[i];
count = malloc(sizeof(int) * (max + 1));
if (!count)
return;
for (i = 0; i <= max; i++)
count[i] = 0;
for (i = 0; i < (int)size; i++)
count[array[i]]++;
for (i = 1; i <= max; i++) /* prefix sum computation */
count[i] += count[i - 1];
print_array(count, max + 1); /* print count array after setup */
output = malloc(sizeof(int) * size);
if (!output)
{
free(count);
return;
}
for (i = size - 1; i >= 0; i--)
{
count[array[i]]--;
output[count[array[i]]] = array[i];
}
for (i = 0; i < (int)size; i++)
array[i] = output[i];
free(count);
free(output);
}