Files
aisd/heapsort.c
T
2025-04-16 17:16:08 +02:00

77 lines
1.4 KiB
C

#include <stdio.h>
#include <stdlib.h>
void Heapify(int A[], int i, int heapsize) {
int left = 2 * i +1;
int right = (2 * i) + 2;
int largest = i;
if (left <= heapsize && A[left] > A[largest]) {
largest = left;
} else {
largest = i;
}
if (right <= heapsize && A[right] > A[largest]) {
largest = right;
}
if (largest != i) {
int temp = A[largest];
A[largest] = A[i];
A[i] = temp;
Heapify(A, largest, heapsize);
}
}
int main() {
int size;
int res = scanf("%d", &size);
if (res != 1) {
fprintf(stderr, "Error reading size\n");
return 1;
}
int *array = malloc(sizeof(int) * size);
for (int i = 0; i < size; i++) {
res = scanf("%d", &array[i]);
if (res != 1) {
fprintf(stderr, "Error reading array element\n");
free(array);
return 1;
}
}
printf("pre heap:");
for (int i = 0; i < size; i++) {
printf("%d ", array[i]);
}
// Build the heap
for (int i = size / 2 - 1; i >= 0; i--) {
Heapify(array, i, size);
}
printf("\npost heap:");
for (int i = 0; i < size; i++) {
printf("%d ", array[i]);
}
int heapsize = size;
for (int i = size - 1; i >= 0; i--) {
int temp = array[i];
array[i] = array[1];
array[1] = temp;
heapsize--;
Heapify(array, i, heapsize);
}
printf("\npost sort:");
for (int i = 0; i < size; i++) {
printf("%d ", array[i]);
}
free(array);
return 0;
}