Mega Code Archive
Qcksort, quick sort [array]
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#include <stdio.h>
#define MAXARRAY 10
void quicksort(int arr[], int low, int high);
int main(void) {
int array[MAXARRAY] = {0};
int i = 0;
/* load some random values into the array */
for(i = 0; i < MAXARRAY; i++)
array[i] = rand() % 100;
/* print the original array */
printf("Before quicksort: ");
for(i = 0; i < MAXARRAY; i++) {
printf(" %d ", array[i]);
}
printf("\n");
quicksort(array, 0, (MAXARRAY - 1));
/* print the `quicksorted' array */
printf("After quicksort: ");
for(i = 0; i < MAXARRAY; i++) {
printf(" %d ", array[i]);
}
printf("\n");
return 0;
}
/* sort everything inbetween `low' <-> `high' */
void quicksort(int arr[], int low, int high) {
int i = low;
int j = high;
int y = 0;
/* compare value */
int z = arr[(low + high) / 2];
/* partition */
do {
/* find member above ... */
while(arr[i] < z) i++;
/* find element below ... */
while(arr[j] > z) j--;
if(i <= j) {
/* swap two elements */
y = arr[i];
arr[i] = arr[j];
arr[j] = y;
i++;
j--;
}
} while(i <= j);
/* recurse */
if(low < j)
quicksort(arr, low, j);
if(i < high)
quicksort(arr, i, high);
}
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