build

chapter_tree/array_representation_of_tree.md

@@ -515,7 +515,90 @@ comments: true
 === "C"
 
     ```c title="array_binary_tree.c"
-    [class]{arrayBinaryTree}-[func]{}
+    /* 数组表示下的二叉树类 */
+    struct arrayBinaryTree {
+        vector *tree;
+    };
+
+    typedef struct arrayBinaryTree arrayBinaryTree;
+
+    /* 构造函数 */
+    arrayBinaryTree *newArrayBinaryTree(vector *arr) {
+        arrayBinaryTree *newABT = malloc(sizeof(arrayBinaryTree));
+        newABT->tree = arr;
+        return newABT;
+    }
+
+    /* 节点数量 */
+    int size(arrayBinaryTree *abt) {
+        return abt->tree->size;
+    }
+
+    /* 获取索引为 i 节点的值 */
+    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;
+        return *(int *)abt->tree->data[i];
+    }
+
+    /* 深度优先遍历 */
+    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;
+        // 前序遍历
+        if (strcmp(order, "pre") == 0) {
+            int tmp = val(abt, i);
+            vectorPushback(res, &tmp, sizeof(tmp));
+        }
+        dfs(abt, left(i), order, res);
+        // 中序遍历
+        if (strcmp(order, "in") == 0) {
+            int tmp = val(abt, i);
+            vectorPushback(res, &tmp, sizeof(tmp));
+        }
+        dfs(abt, right(i), order, res);
+        // 后序遍历
+        if (strcmp(order, "post") == 0) {
+            int tmp = val(abt, i);
+            vectorPushback(res, &tmp, sizeof(tmp));
+        }
+    }
+
+    /* 层序遍历 */
+    vector *levelOrder(arrayBinaryTree *abt) {
+        vector *res = newVector();
+        // 直接遍历数组
+        for (int i = 0; i < size(abt); i++) {
+            if (val(abt, i) != INT_MAX) {
+                int tmp = val(abt, i);
+                vectorPushback(res, &tmp, sizeof(int));
+            }
+        }
+        return res;
+    }
+
+    /* 前序遍历 */
+    vector *preOrder(arrayBinaryTree *abt) {
+        vector *res = newVector();
+        dfs(abt, 0, "pre", res);
+        return res;
+    }
+
+    /* 中序遍历 */
+    vector *inOrder(arrayBinaryTree *abt) {
+        vector *res = newVector();
+        dfs(abt, 0, "in", res);
+        return res;
+    }
+
+    /* 后序遍历 */
+    vector *postOrder(arrayBinaryTree *abt) {
+        vector *res = newVector();
+        dfs(abt, 0, "post", res);
+        return res;
+    }
     ```
 
 === "C#"