'248-250'

DengBoCong · DengBoCong · commit c06cd86e0d04 · 2022-06-24T22:53:57.000+08:00
diff --git a/README.md b/README.md
@@ -549,3 +549,9 @@ $=link=$: 题目原题链接
 
 247.[盛最多水的容器](https://leetcode.cn/problems/container-with-most-water/)（[Java解法](https://github.com/DengBoCong/Algorithm/blob/master/core/ContainerWithMostWater/ContainerWithMostWater.java) | [Python解法](https://github.com/DengBoCong/Algorithm/blob/master/core/ContainerWithMostWater/ContainerWithMostWater.py)）：题目难度(中等)，题目类型(贪心_数组_双指针)
 
+248.[在每个树行中找最大值](https://leetcode.cn/problems/find-largest-value-in-each-tree-row/)（[Java解法](https://github.com/DengBoCong/Algorithm/blob/master/core/FindLargestValueInEachTreeRow/FindLargestValueInEachTreeRow.java) | [Python解法](https://github.com/DengBoCong/Algorithm/blob/master/core/FindLargestValueInEachTreeRow/FindLargestValueInEachTreeRow.py)）：题目难度(中等)，题目类型(树_深度优先搜索_广度优先搜索_二叉树)
+
+249.[删除二叉搜索树中的节点](https://leetcode.cn/problems/delete-node-in-a-bst/)（[Java解法](https://github.com/DengBoCong/Algorithm/blob/master/core/DeleteNodeInABst/DeleteNodeInABst.java) | [Python解法](https://github.com/DengBoCong/Algorithm/blob/master/core/DeleteNodeInABst/DeleteNodeInABst.py)）：题目难度(中等)，题目类型(树_二叉搜索树_二叉树)
+
+250.[验证回文串](https://leetcode.cn/problems/valid-palindrome/)（[Java解法](https://github.com/DengBoCong/Algorithm/blob/master/core/ValidPalindrome/ValidPalindrome.java) | [Python解法](https://github.com/DengBoCong/Algorithm/blob/master/core/ValidPalindrome/ValidPalindrome.py)）：题目难度(简单)，题目类型(双指针_字符串)
+
diff --git a/core/DeleteNodeInABst/DeleteNodeInABst.java b/core/DeleteNodeInABst/DeleteNodeInABst.java
@@ -0,0 +1,38 @@
+package com.dbc.code;
+
+public class DeleteNodeInABst {
+    public class TreeNode {
+        int val;
+        TreeNode left;
+        TreeNode right;
+
+        TreeNode() {
+        }
+
+        TreeNode(int val) {
+            this.val = val;
+        }
+
+        TreeNode(int val, TreeNode left, TreeNode right) {
+            this.val = val;
+            this.left = left;
+            this.right = right;
+        }
+    }
+
+    public TreeNode deleteNode(TreeNode root, int key) {
+        if (root == null) return null;
+        else if (root.val < key) root.right = deleteNode(root.right, key);
+        else if (root.val > key) root.left = deleteNode(root.left, key);
+        else if (root.left == null || root.right == null) root = root.left != null ? root.left : root.right;
+        else {
+            TreeNode node = root.right;
+            while (node.left != null) {
+                node = node.left;
+            }
+            node.left = root.left;
+            return root.right;
+        }
+        return root;
+    }
+}
diff --git a/core/DeleteNodeInABst/DeleteNodeInABst.py b/core/DeleteNodeInABst/DeleteNodeInABst.py
@@ -0,0 +1,27 @@
+from typing import Optional
+
+class TreeNode:
+    def __init__(self, val=0, left=None, right=None):
+        self.val = val
+        self.left = left
+        self.right = right
+
+def deleteNode(root: Optional[TreeNode], key: int) -> Optional[TreeNode]:
+    if root is None:
+        return None
+    elif root.val > key:
+        root.left = deleteNode(root.left, key)
+    elif root.val < key:
+        root.right = deleteNode(root.right, key)
+    elif root.left is None or root.right is None:
+        root = root.left if root.left else root.right
+    else:
+        node = root.right
+        while node.left:
+            node = node.left
+        node.left = root.left
+        return root.right
+    return root
+
+
+
diff --git a/core/FindLargestValueInEachTreeRow/FindLargestValueInEachTreeRow.java b/core/FindLargestValueInEachTreeRow/FindLargestValueInEachTreeRow.java
@@ -0,0 +1,46 @@
+package com.dbc.code;
+
+import java.util.ArrayDeque;
+import java.util.ArrayList;
+import java.util.Deque;
+import java.util.List;
+
+public class FindLargestValueInEachTreeRow {
+    public class TreeNode {
+        int val;
+        TreeNode left;
+        TreeNode right;
+
+        TreeNode() {
+        }
+
+        TreeNode(int val) {
+            this.val = val;
+        }
+
+        TreeNode(int val, TreeNode left, TreeNode right) {
+            this.val = val;
+            this.left = left;
+            this.right = right;
+        }
+    }
+
+    public List<Integer> largestValues(TreeNode root) {
+        if (root == null) return new ArrayList<>();
+        Deque<TreeNode> queue = new ArrayDeque<>();
+        queue.add(root);
+        List<Integer> res = new ArrayList<>();
+        while (!queue.isEmpty()) {
+            int length = queue.size();
+            int max = Integer.MIN_VALUE;
+            for (int i = 0; i < length; i++) {
+                TreeNode node = queue.pollFirst();
+                max = Math.max(max, node.val);
+                if (node.left != null) queue.add(node.left);
+                if (node.right != null) queue.add(node.right);
+            }
+            res.add(max);
+        }
+        return res;
+    }
+}
diff --git a/core/FindLargestValueInEachTreeRow/FindLargestValueInEachTreeRow.py b/core/FindLargestValueInEachTreeRow/FindLargestValueInEachTreeRow.py
@@ -0,0 +1,28 @@
+from typing import Optional, List
+from collections import deque
+
+class TreeNode:
+    def __init__(self, val=0, left=None, right=None):
+        self.val = val
+        self.left = left
+        self.right = right
+
+def largestValues(root: Optional[TreeNode]) -> List[int]:
+    if not root:
+        return []
+    queue = deque([root])
+    res = []
+    while queue:
+        length, layer_max = len(queue), -2 ** 31
+        for i in range(length):
+            node = queue.popleft()
+            if node.left:
+                queue.append(node.left)
+            if node.right:
+                queue.append(node.right)
+            layer_max = max(layer_max, node.val)
+        res.append(layer_max)
+
+    return res
+
+
diff --git a/core/ValidPalindrome/ValidPalindrome.java b/core/ValidPalindrome/ValidPalindrome.java
@@ -0,0 +1,20 @@
+package com.dbc.code;
+
+import java.util.Locale;
+
+public class ValidPalindrome {
+    public boolean isPalindrome(String s) {
+        int left = 0, right = s.length() - 1;
+        s = s.toLowerCase();
+        while (left < right) {
+            while (left < right && !Character.isDigit(s.charAt(left)) && !Character.isLetter(s.charAt(left))) left++;
+            while (left < right && !Character.isDigit(s.charAt(right)) && !Character.isLetter(s.charAt(right))) right--;
+            if (left < right && s.charAt(left) != s.charAt(right)) {
+                return false;
+            }
+            left++;
+            right--;
+        }
+        return true;
+    }
+}
diff --git a/core/ValidPalindrome/ValidPalindrome.py b/core/ValidPalindrome/ValidPalindrome.py
@@ -0,0 +1,16 @@
+def isPalindrome(s: str) -> bool:
+    left, right = 0, len(s) - 1
+    s = s.lower()
+    while left < right:
+        while left < right and not s[left].isdigit() and not s[left].isalpha():
+            left += 1
+        while left < right and not s[right].isdigit() and not s[right].isalpha():
+            right -= 1
+        if left < right and s[left] != s[right]:
+            return False
+        left += 1
+        right -= 1
+    return True
+
+
+
