added a generic min heap with a custom comparator

coders/heap.c

@@ -0,0 +1,91 @@
+#include "codexion.h"
+#include <stdbool.h>
+#include <stdlib.h>
+
+static void	sift_up(t_minheap *heap, int i, int (*cmp)(void *, void *))
+{
+	int		parent;
+	void	*temp;
+
+	while (i > 0)
+	{
+		parent = (i - 1) / 2;
+		if (cmp(heap->array[parent], heap->array[i]) > 0)
+		{
+			temp = heap->array[parent];
+			heap->array[parent] = heap->array[i];
+			heap->array[i] = temp;
+			i = parent;
+		}
+		else
+			break ;
+	}
+}
+
+static void	sift_down(t_minheap *heap, int i, int (*cmp)(void *, void *))
+{
+	int		smallest;
+	int		left;
+	int		right;
+	void	*temp;
+
+	while (true)
+	{
+		smallest = i;
+		left = 2 * i + 1;
+		right = 2 * i + 2;
+		if (left < heap->length && cmp(heap->array[left],
+				heap->array[smallest]) < 0)
+			smallest = left;
+		if (right < heap->length && cmp(heap->array[right],
+				heap->array[smallest]) < 0)
+			smallest = right;
+		if (smallest == i)
+			break ;
+		temp = heap->array[smallest];
+		heap->array[smallest] = heap->array[i];
+		heap->array[i] = temp;
+		i = smallest;
+	}
+}
+
+t_minheap	*init_heap(int (*cmp)(void *, void *))
+{
+	t_minheap	*heap;
+
+	heap = malloc(sizeof(t_minheap));
+	if (!heap)
+		return (NULL);
+	heap->length = 0;
+	heap->cmp = cmp;
+	return (heap);
+}
+
+void	*peek(t_minheap *heap)
+{
+	if (!heap || !heap->length)
+		return (NULL);
+	return (heap->array[0]);
+}
+
+void	enqueue(t_minheap *heap, void *val)
+{
+	if (heap->length >= HEAP_SIZE)
+		return ;
+	heap->array[heap->length] = val;
+	heap->length++;
+	sift_up(heap, heap->length - 1, heap->cmp);
+}
+
+void	*dequeue(t_minheap *heap)
+{
+	void	*temp;
+
+	if (!heap || !heap->length)
+		return (NULL);
+	temp = heap->array[0];
+	heap->array[0] = heap->array[heap->length - 1];
+	heap->length--;
+	sift_down(heap, 0, heap->cmp);
+	return (temp);
+}