Update array.c

3 changes:
1. In the enlarge part, I didn't change because I didn't find a good way to deal with the local variable and the clear definition. malloc is commonly used in LeetCode so I think it is not bad for a beginner.
2. I changed the initialization of the second array to make it in the same style as C++.
3. In the enlarge part in main, I deleted the code of pointer free to match the array operations. I also changed the operate array in the later part because the enlarged array cannot be assigned to the older array name.

BTW, sorry for updating so late. Reading different version documents and book are really tiring and boring.

codes/c/chapter_array_and_linkedlist/array.c

@@ -76,16 +76,7 @@ int main() {
     printf("数组 arr = ");
     printArray(arr, size);
 
-    int arr2[5] = { 1, 3, 2, 5, 4 };
-    printf("数组 arr2 = ");
-    printArray(arr2, size);
-
-    int* nums = (int *)malloc(sizeof(int) * size);
-    nums[0] = 1;
-    nums[1] = 3;
-    nums[2] = 2;
-    nums[3] = 5;
-    nums[4] = 4;
+    int nums[5] = { 1, 3, 2, 5, 4 };
     printf("数组 nums = ");
     printArray(nums, size);
     
@@ -96,29 +87,26 @@ int main() {
     /* 长度扩展 */
     int enlarge = 3;
     int* res = extend(nums, size, enlarge);
-    int* temp = nums;
-    nums = res;
-    free(temp);
     size += enlarge;
     printf("将数组长度扩展至 8 ，得到 nums = ");
-    printArray(nums, size);
+    printArray(res, size);
     
     /* 插入元素 */
-    insert(nums, size, 6, 3);
+    insert(res, size, 6, 3);
     printf("在索引 3 处插入数字 6 ，得到 nums = ");
-    printArray(nums, size);
+    printArray(res, size);
 
     /* 删除元素 */
-    removeItem(nums, size, 2);
+    removeItem(res, size, 2);
     printf("删除索引 2 处的元素，得到 nums = ");
-    printArray(nums, size);
+    printArray(res, size);
     
     /* 遍历数组 */
-    traverse(nums, size);
+    traverse(res, size);
     
     /* 查找元素 */
-    int index = find(nums, size, 3);
-    printf("在 nums 中查找元素 3 ，得到索引 = %d\n", index);
+    int index = find(res, size, 3);
+    printf("在 res 中查找元素 3 ，得到索引 = %d\n", index);
 
     return 0;
 }