Merge pull request algorithm004-01#430 from AceXu/master

melody-li · web-flow · commit bf743b2d8ac6 · 2019-10-28T11:50:35.000+08:00
666-week 02
diff --git a/Week 02/id_666/LeetCode_242_666.java b/Week 02/id_666/LeetCode_242_666.java
@@ -0,0 +1,27 @@
+class Solution {
+    public boolean isAnagram(String s, String t) {
+        //判断字符长度是否相等
+        if(s.length() != t.length()) {
+            return false;
+        }
+
+        if (s.length() == 0 || t.length() == 0) {
+            return false;
+        }
+
+        //统计每个字母出现的频次,字符相减
+        int[] nums = new int[26];
+        for (int i = 0; i < s.length(); i++) {
+            nums[s.charAt(i) - 'a']++;
+            nums[t.charAt(i) - 'a']--;
+        }
+
+        for (int num : nums) {
+            if (num != 0) {
+                return false;
+            }
+        }
+
+        return true;
+    }
+}
diff --git a/Week 02/id_666/LeetCode_94_666.java b/Week 02/id_666/LeetCode_94_666.java
@@ -0,0 +1,23 @@
+/**
+ * 二叉树中序遍历
+ **/
+class Solution {
+    public List<Integer> inorderTraversal(TreeNode root) {
+        List < Integer > res = new ArrayList < > ();
+        helper(root, res);
+        return res;
+    }
+
+    //不是很懂，默写代码
+    public void helper(TreeNode root, List < Integer > res) {
+        if (root != null) {
+            if (root.left != null) {
+                helper(root.left, res);
+            }
+            res.add(root.val);
+            if (root.right != null) {
+                helper(root.right, res);
+            }
+        }
+    }
+}
