Simplify struct declarations of C.

Use PascalCase for all structs in C.
SImplify n_queens.c
Format C code for chapter of graph.

codes/c/chapter_tree/array_binary_tree.c

@@ -7,26 +7,24 @@
 #include "../utils/common.h"
 
 /* 数组表示下的二叉树类 */
-struct arrayBinaryTree {
+typedef struct {
     vector *tree;
-};
-
-typedef struct arrayBinaryTree arrayBinaryTree;
+} ArrayBinaryTree;
 
 /* 构造函数 */
-arrayBinaryTree *newArrayBinaryTree(vector *arr) {
-    arrayBinaryTree *newABT = malloc(sizeof(arrayBinaryTree));
+ArrayBinaryTree *newArrayBinaryTree(vector *arr) {
+    ArrayBinaryTree *newABT = malloc(sizeof(ArrayBinaryTree));
     newABT->tree = arr;
     return newABT;
 }
 
 /* 节点数量 */
-int size(arrayBinaryTree *abt) {
+int size(ArrayBinaryTree *abt) {
     return abt->tree->size;
 }
 
 /* 获取索引为 i 节点的值 */
-int val(arrayBinaryTree *abt, int i) {
+int val(ArrayBinaryTree *abt, int i) {
     // 若索引越界，则返回 INT_MAX ，代表空位
     if (i < 0 || i >= size(abt))
         return INT_MAX;
@@ -49,7 +47,7 @@ int parent(int i) {
 }
 
 /* 深度优先遍历 */
-void dfs(arrayBinaryTree *abt, int i, const char *order, vector *res) {
+void dfs(ArrayBinaryTree *abt, int i, const char *order, vector *res) {
     // 若为空位，则返回
     if (val(abt, i) == INT_MAX)
         return;
@@ -73,7 +71,7 @@ void dfs(arrayBinaryTree *abt, int i, const char *order, vector *res) {
 }
 
 /* 层序遍历 */
-vector *levelOrder(arrayBinaryTree *abt) {
+vector *levelOrder(ArrayBinaryTree *abt) {
     vector *res = newVector();
     // 直接遍历数组
     for (int i = 0; i < size(abt); i++) {
@@ -86,21 +84,21 @@ vector *levelOrder(arrayBinaryTree *abt) {
 }
 
 /* 前序遍历 */
-vector *preOrder(arrayBinaryTree *abt) {
+vector *preOrder(ArrayBinaryTree *abt) {
     vector *res = newVector();
     dfs(abt, 0, "pre", res);
     return res;
 }
 
 /* 中序遍历 */
-vector *inOrder(arrayBinaryTree *abt) {
+vector *inOrder(ArrayBinaryTree *abt) {
     vector *res = newVector();
     dfs(abt, 0, "in", res);
     return res;
 }
 
 /* 后序遍历 */
-vector *postOrder(arrayBinaryTree *abt) {
+vector *postOrder(ArrayBinaryTree *abt) {
     vector *res = newVector();
     dfs(abt, 0, "post", res);
     return res;
@@ -129,7 +127,7 @@ int main() {
         vectorPushback(vArr, &arr[i], sizeof(int));
     }
     // 数组表示下的二叉树类
-    arrayBinaryTree *abt = newArrayBinaryTree(vArr);
+    ArrayBinaryTree *abt = newArrayBinaryTree(vArr);
 
     // 访问节点
     int i = 1;

codes/c/chapter_tree/avl_tree.c

@@ -7,15 +7,13 @@
 #include "../utils/common.h"
 
 /* AVL Tree */
-struct aVLTree {
+typedef struct {
     TreeNode *root;
-};
-
-typedef struct aVLTree aVLTree;
+} AVLTree;
 
 /* 构建 AVL 树 */
-aVLTree *newAVLTree() {
-    aVLTree *tree = (aVLTree *)malloc(sizeof(aVLTree));
+AVLTree *newAVLTree() {
+    AVLTree *tree = (AVLTree *)malloc(sizeof(AVLTree));
     tree->root = NULL;
     return tree;
 }
@@ -134,7 +132,7 @@ TreeNode *insertHelper(TreeNode *node, int val) {
 }
 
 /* 插入节点 */
-void insert(aVLTree *tree, int val) {
+void insert(AVLTree *tree, int val) {
     tree->root = insertHelper(tree->root, val);
 }
 
@@ -183,12 +181,12 @@ TreeNode *removeHelper(TreeNode *node, int val) {
 
 /* 删除节点 */
 // 由于引入了 stdio.h ，此处无法使用 remove 关键词
-void removeItem(aVLTree *tree, int val) {
+void removeItem(AVLTree *tree, int val) {
     TreeNode *root = removeHelper(tree->root, val);
 }
 
 /* 查找节点 */
-TreeNode *search(aVLTree *tree, int val) {
+TreeNode *search(AVLTree *tree, int val) {
     TreeNode *cur = tree->root;
     // 循环查找，越过叶节点后跳出
     while (cur != NULL) {
@@ -207,13 +205,13 @@ TreeNode *search(aVLTree *tree, int val) {
     return cur;
 }
 
-void testInsert(aVLTree *tree, int val) {
+void testInsert(AVLTree *tree, int val) {
     insert(tree, val);
     printf("\n插入节点 %d 后，AVL 树为 \n", val);
     printTree(tree->root);
 }
 
-void testRemove(aVLTree *tree, int val) {
+void testRemove(AVLTree *tree, int val) {
     removeItem(tree, val);
     printf("\n删除节点 %d 后，AVL 树为 \n", val);
     printTree(tree->root);
@@ -222,7 +220,7 @@ void testRemove(aVLTree *tree, int val) {
 /* Driver Code */
 int main() {
     /* 初始化空 AVL 树 */
-    aVLTree *tree = (aVLTree *)newAVLTree();
+    AVLTree *tree = (AVLTree *)newAVLTree();
     /* 插入节点 */
     // 请关注插入节点后，AVL 树是如何保持平衡的
     testInsert(tree, 1);

codes/c/chapter_tree/binary_search_tree.c

@@ -7,11 +7,9 @@
 #include "../utils/common.h"
 
 /* 二叉搜索树 */
-struct binarySearchTree {
+typedef struct {
     TreeNode *root;
-};
-
-typedef struct binarySearchTree binarySearchTree;
+} BinarySearchTree;
 
 /* 比较器：从小到大排序 */
 int sortIntHelper(const void *a, const void *b) {
@@ -32,8 +30,8 @@ TreeNode *buildTree(int nums[], int i, int j) {
     return root;
 }
 
-binarySearchTree *newBinarySearchTree(int nums[], int size) {
-    binarySearchTree *bst = (binarySearchTree *)malloc(sizeof(binarySearchTree));
+BinarySearchTree *newBinarySearchTree(int nums[], int size) {
+    BinarySearchTree *bst = (BinarySearchTree *)malloc(sizeof(BinarySearchTree));
     TreeNode *root;
     // 从小到大排序数组
     qsort(nums, size, sizeof(int), sortIntHelper);
@@ -44,12 +42,12 @@ binarySearchTree *newBinarySearchTree(int nums[], int size) {
 }
 
 /* 获取二叉树根节点 */
-TreeNode *getRoot(binarySearchTree *bst) {
+TreeNode *getRoot(BinarySearchTree *bst) {
     return bst->root;
 }
 
 /* 查找节点 */
-TreeNode *search(binarySearchTree *bst, int num) {
+TreeNode *search(BinarySearchTree *bst, int num) {
     TreeNode *cur = bst->root;
     // 循环查找，越过叶节点后跳出
     while (cur != NULL) {
@@ -69,7 +67,7 @@ TreeNode *search(binarySearchTree *bst, int num) {
 }
 
 /* 插入节点 */
-void insert(binarySearchTree *bst, int num) {
+void insert(BinarySearchTree *bst, int num) {
     // 若树为空，则初始化根节点
     if (bst->root == NULL) {
         bst->root = newTreeNode(num);
@@ -102,7 +100,7 @@ void insert(binarySearchTree *bst, int num) {
 
 /* 删除节点 */
 // 由于引入了 stdio.h ，此处无法使用 remove 关键词
-void removeItem(binarySearchTree *bst, int num) {
+void removeItem(BinarySearchTree *bst, int num) {
     // 若树为空，直接提前返回
     if (bst->root == NULL)
         return;
@@ -154,7 +152,7 @@ void removeItem(binarySearchTree *bst, int num) {
 int main() {
     /* 初始化二叉搜索树 */
     int nums[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15};
-    binarySearchTree *bst = newBinarySearchTree(nums, sizeof(nums) / sizeof(int));
+    BinarySearchTree *bst = newBinarySearchTree(nums, sizeof(nums) / sizeof(int));
     printf("初始化的二叉树为\n");
     printTree(getRoot(bst));