BIGO-IsBst

Author: ChlZhYa

Interview/BIGO-IsBst/src/Solution.java

@@ -0,0 +1,50 @@
+/**
+ * @author changleamazing
+ * @date 2020/10/26 20:26
+ **/
+public class Solution {
+
+    static boolean isBST = true;
+
+    /**
+     * 是否是二叉搜索树
+     * @param node
+     * @return
+     */
+    private boolean isBinarySearchTree(TreeNode node) {
+        recursive(node);
+        return isBST;
+    }
+
+    /**
+     * 递归遍历节点
+     * @param node
+     */
+    private void recursive(TreeNode node) {
+        if (node == null) {
+            return;
+        }
+        // 左节点不为空且大于等于父节点，则修改标识
+        if (node.left != null && node.left.val >= node.val) {
+            isBST = false;
+        }
+        recursive(node.left);
+        // 右节点不为空且小于等于父节点，则修改标识
+        if (node.right != null && node.right.val <= node.val) {
+            isBST = false;
+        }
+        recursive(node.right);
+    }
+
+}
+
+class TreeNode {
+
+    int val;
+    TreeNode left;
+    TreeNode right;
+
+    TreeNode(int x) {
+        val = x;
+    }
+}