中序遍历

src/leecode/tree/No94.java

@@ -0,0 +1,27 @@
+package leecode.tree;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Stack;
+
+/**
+ * 二叉树的中序遍历
+ */
+public class No94 {
+    public List<Integer> inorderTraversal(TreeNode root) {
+        List<Integer> ret = new ArrayList<>();
+        Stack<TreeNode> stack = new Stack<>();
+        TreeNode cur = root;
+        while (cur != null || !stack.isEmpty()) {
+            if (cur != null) {
+                stack.push(cur);
+                cur = cur.left;
+            } else {
+                cur = stack.pop();
+                ret.add(cur.val);
+                cur = cur.right;
+            }
+        }
+        return ret;
+    }
+}