From 3594109c970a1dc77bfafb62c05b98defdf4e6dd Mon Sep 17 00:00:00 2001
From: mhs-m <1923153170@qq.com>
Date: Wed, 27 May 2026 22:17:52 +0800
Subject: [PATCH] Heap sort builds a max heap from the array, then repeatedly
 swaps the root (largest) with the last unsorted element and heapifies the
 reduced heap to sort in place with O(n log n) time.

---
 Algorithms/C/heap_sort.c | 68 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 68 insertions(+)
 create mode 100644 Algorithms/C/heap_sort.c

diff --git a/Algorithms/C/heap_sort.c b/Algorithms/C/heap_sort.c
new file mode 100644
index 00000000..366101bd
--- /dev/null
+++ b/Algorithms/C/heap_sort.c
@@ -0,0 +1,68 @@
+// heap_sort.c
+// 堆排序（最大堆实现升序）
+
+#include <stdio.h>
+
+// 交换两个整数
+void swap(int* a, int* b) {
+    int temp = *a;
+    *a = *b;
+    *b = temp;
+}
+
+// 堆化（调整以i为根的子树为最大堆）
+// n: 堆的大小, i: 当前节点索引
+void heapify(int arr[], int n, int i) {
+    int largest = i;       // 初始化最大为根
+    int left = 2 * i + 1;
+    int right = 2 * i + 2;
+
+    // 左孩子大于根
+    if (left < n && arr[left] > arr[largest])
+        largest = left;
+
+    // 右孩子大于当前最大
+    if (right < n && arr[right] > arr[largest])
+        largest = right;
+
+    // 如果最大值不是根，交换并递归调整
+    if (largest != i) {
+        swap(&arr[i], &arr[largest]);
+        heapify(arr, n, largest);
+    }
+}
+
+// 堆排序主函数
+void heap_sort(int arr[], int n) {
+    // 构建最大堆（从最后一个非叶子节点开始）
+    for (int i = n / 2 - 1; i >= 0; i--)
+        heapify(arr, n, i);
+
+    // 一个个取出元素：将堆顶（最大值）移到数组末尾，再调整剩余堆
+    for (int i = n - 1; i > 0; i--) {
+        swap(&arr[0], &arr[i]);   // 当前最大值放到末尾
+        heapify(arr, i, 0);       // 在缩小后的堆上调整
+    }
+}
+
+// 打印数组
+void print_array(int arr[], int size) {
+    for (int i = 0; i < size; i++)
+        printf("%d ", arr[i]);
+    printf("\n");
+}
+
+// 测试示例
+int main() {
+    int arr[] = { 12, 11, 13, 5, 6, 7 };
+    int n = sizeof(arr) / sizeof(arr[0]);
+
+    printf("原始数组: ");
+    print_array(arr, n);
+
+    heap_sort(arr, n);
+
+    printf("排序后: ");
+    print_array(arr, n);
+    return 0;
+}
\ No newline at end of file