add 909 918 2938

Author: 2xiao

assets/output/0427.md

@@ -2,7 +2,6 @@
 
 🟠 <font color=#ffb800>Medium</font>&emsp; 🔖&ensp; [`树`](/leetcode/outline/tag/tree.md) [`数组`](/leetcode/outline/tag/array.md) [`分治`](/leetcode/outline/tag/divide-and-conquer.md) [`矩阵`](/leetcode/outline/tag/matrix.md)&emsp; 🔗&ensp;[`LeetCode`](https://leetcode.com/problems/construct-quad-tree)
 
-
 ## 题目
 
 Given a `n * n` matrix `grid` of `0's` and `1's` only. We want to represent
@@ -13,42 +12,26 @@ Return _the root of the Quad-Tree representing_`grid`.
 A Quad-Tree is a tree data structure in which each internal node has exactly
 four children. Besides, each node has two attributes:
 
-  * `val`: True if the node represents a grid of 1's or False if the node represents a grid of 0's. Notice that you can assign the `val` to True or False when `isLeaf` is False, and both are accepted in the answer.
-  * `isLeaf`: True if the node is a leaf node on the tree or False if the node has four children.
-
-> 
-> 
-> 
-> 
-> 
-> class Node {
-> 
-> > 
-> public boolean val;
-> 
-> > 
-> public boolean isLeaf;
-> 
-> > 
-> public Node topLeft;
-> 
-> > 
-> public Node topRight;
-> 
-> > 
-> public Node bottomLeft;
-> 
-> > 
-> public Node bottomRight;
-> 
-> }
+- `val`: True if the node represents a grid of 1's or False if the node represents a grid of 0's. Notice that you can assign the `val` to True or False when `isLeaf` is False, and both are accepted in the answer.
+- `isLeaf`: True if the node is a leaf node on the tree or False if the node has four children.
+
+```
+class Node {
+    public boolean val;
+    public boolean isLeaf;
+    public Node topLeft;
+    public Node topRight;
+    public Node bottomLeft;
+    public Node bottomRight;
+}
+```
 
 We can construct a Quad-Tree from a two-dimensional area using the following
 steps:
 
-  1. If the current grid has the same value (i.e all `1's` or all `0's`) set `isLeaf` True and set `val` to the value of the grid and set the four children to Null and stop.
-  2. If the current grid has different values, set `isLeaf` to False and set `val` to any value and divide the current grid into four sub-grids as shown in the photo.
-  3. Recurse for each of the children with the proper sub-grid.
+1. If the current grid has the same value (i.e all `1's` or all `0's`) set `isLeaf` True and set `val` to the value of the grid and set the four children to Null and stop.
+2. If the current grid has different values, set `isLeaf` to False and set `val` to any value and divide the current grid into four sub-grids as shown in the photo.
+3. Recurse for each of the children with the proper sub-grid.
 
 ![](https://assets.leetcode.com/uploads/2020/02/11/new_top.png)
 
@@ -69,89 +52,70 @@ If the value of `isLeaf` or `val` is True we represent it as **1** in the list
 `[isLeaf, val]` and if the value of `isLeaf` or `val` is False we represent it
 as **0**.
 
-
-
 **Example 1:**
 
 ![](https://assets.leetcode.com/uploads/2020/02/11/grid1.png)
 
 > Input: grid = [[0,1],[1,0]]
-> 
+>
 > Output: [[0,1],[1,0],[1,1],[1,1],[1,0]]
-> 
+>
 > Explanation: The explanation of this example is shown below:
-> 
+>
 > Notice that 0 represents False and 1 represents True in the photo representing the Quad-Tree.
-> 
+>
 > ![](https://assets.leetcode.com/uploads/2020/02/12/e1tree.png)
 
 **Example 2:**
 
 ![](https://assets.leetcode.com/uploads/2020/02/12/e2mat.png)
 
 > Input: grid = [[1,1,1,1,0,0,0,0],[1,1,1,1,0,0,0,0],[1,1,1,1,1,1,1,1],[1,1,1,1,1,1,1,1],[1,1,1,1,0,0,0,0],[1,1,1,1,0,0,0,0],[1,1,1,1,0,0,0,0],[1,1,1,1,0,0,0,0]]
-> 
+>
 > Output: [[0,1],[1,1],[0,1],[1,1],[1,0],null,null,null,null,[1,0],[1,0],[1,1],[1,1]]
-> 
+>
 > Explanation: All values in the grid are not the same. We divide the grid into four sub-grids.
-> 
+>
 > The topLeft, bottomLeft and bottomRight each has the same value.
-> 
+>
 > The topRight have different values so we divide it into 4 sub-grids where each has the same value.
-> 
+>
 > Explanation is shown in the photo below:
-> 
+>
 > ![](https://assets.leetcode.com/uploads/2020/02/12/e2tree.png)
 
 **Constraints:**
 
-  * `n == grid.length == grid[i].length`
-  * `n == 2x` where `0 <= x <= 6`
-
+- `n == grid.length == grid[i].length`
+- `n == 2^x` where `0 <= x <= 6`
 
 ## 题目大意
 
 给你一个 `n * n` 矩阵 `grid` ，矩阵由若干 `0` 和 `1` 组成。请你用四叉树表示该矩阵 `grid` 。
 
-你需要返回能表示矩阵 `grid` 的 四叉树 的根结点。
+你需要返回能表示矩阵 `grid` 的 **四叉树** 的根结点。
 
 四叉树数据结构中，每个内部节点只有四个子节点。此外，每个节点都有两个属性：
 
-  * `val`：储存叶子结点所代表的区域的值。1 对应 **True** ，0 对应 **False** 。注意，当 `isLeaf` 为 **False** 时，你可以把 **True** 或者 **False** 赋值给节点，两种值都会被判题机制 **接受** 。
-  * `isLeaf`: 当这个节点是一个叶子结点时为 **True** ，如果它有 4 个子节点则为 **False** 。
-
-> 
-> 
-> 
-> 
-> 
-> class Node {
-> 
-> > 
-> public boolean val;
-> 
-> > 
-> public boolean isLeaf;
-> 
-> > 
-> public Node topLeft;
-> 
-> > 
-> public Node topRight;
-> 
-> > 
-> public Node bottomLeft;
-> 
-> > 
-> public Node bottomRight;
-> 
-> }
+- `val`：储存叶子结点所代表的区域的值。`1` 对应 **True** ，`0` 对应 **False** 。注意，当 `isLeaf` 为 **False** 时，你可以把 **True** 或者 **False** 赋值给节点，两种值都会被判题机制 **接受** 。
+- `isLeaf`: 当这个节点是一个叶子结点时为 **True** ，如果它有 `4` 个子节点则为 **False** 。
+
+```
+class Node {
+    public boolean val;
+    public boolean isLeaf;
+    public Node topLeft;
+    public Node topRight;
+    public Node bottomLeft;
+    public Node bottomRight;
+}
+```
 
 我们可以按以下步骤为二维区域构建四叉树：
 
-  1. 如果当前网格的值相同（即，全为 `0` 或者全为 `1`），将 `isLeaf` 设为 True ，将 `val` 设为网格相应的值，并将四个子节点都设为 Null 然后停止。
-  2. 如果当前网格的值不同，将 `isLeaf` 设为 False， 将 `val` 设为任意值，然后如下图所示，将当前网格划分为四个子网格。
-  3. 使用适当的子网格递归每个子节点。
+1. 如果当前网格的值相同（即，全为 `0` 或者全为 `1`），将 `isLeaf` 设为 True ，将 `val` 设为网格相应的值，并将四个子节点都设为 Null 然后停止。
+2. 如果当前网格的值不同，将 `isLeaf` 设为 False， 将 `val` 设为任意值，然后如下图所示，将当前网格划分为四个子网格。
+3. 使用适当的子网格递归每个子节点。
 
 ![](https://assets.leetcode.com/uploads/2020/02/11/new_top.png)
 
@@ -165,63 +129,44 @@ as **0**.
 它与二叉树的序列化非常相似。唯一的区别是节点以列表形式表示 `[isLeaf, val]` 。
 
 如果 `isLeaf` 或者 `val` 的值为 True ，则表示它在列表 `[isLeaf, val]` 中的值为 **1** ；如果 `isLeaf`
-或者 `val` 的值为 False ，则表示值为 **0** 。
-
-
+或者 `val` 的值为 `False` ，则表示值为 **0** 。
 
 **示例 1：**
 
 ![](https://assets.leetcode.com/uploads/2020/02/11/grid1.png)
 
-> 
-> 
-> 
-> 
-> 
 > **输入：** grid = [[0,1],[1,0]]
-> 
+>
 > **输出：**[[0,1],[1,0],[1,1],[1,1],[1,0]]
-> 
+>
 > **解释：** 此示例的解释如下：
-> 
+>
 > 请注意，在下面四叉树的图示中，0 表示 false，1 表示 True 。
-> 
+>
 > ![](https://assets.leetcode.com/uploads/2020/02/12/e1tree.png)
-> 
-> 
 
 **示例 2：**
 
 ![](https://assets.leetcode.com/uploads/2020/02/12/e2mat.png)
 
-> 
-> 
-> 
-> 
-> 
 > **输入：** grid = [[1,1,1,1,0,0,0,0],[1,1,1,1,0,0,0,0],[1,1,1,1,1,1,1,1],[1,1,1,1,1,1,1,1],[1,1,1,1,0,0,0,0],[1,1,1,1,0,0,0,0],[1,1,1,1,0,0,0,0],[1,1,1,1,0,0,0,0]]
-> 
+>
 > **输出：**[[0,1],[1,1],[0,1],[1,1],[1,0],null,null,null,null,[1,0],[1,0],[1,1],[1,1]]
-> 
+>
 > **解释：** 网格中的所有值都不相同。我们将网格划分为四个子网格。
-> 
+>
 > topLeft，bottomLeft 和 bottomRight 均具有相同的值。
-> 
+>
 > topRight 具有不同的值，因此我们将其再分为 4 个子网格，这样每个子网格都具有相同的值。
-> 
+>
 > 解释如下图所示：
-> 
+>
 > ![](https://assets.leetcode.com/uploads/2020/02/12/e2tree.png)
-> 
-> 
-
-
 
 **提示：**
 
-  1. `n == grid.length == grid[i].length`
-  2. `n == 2x` 其中 `0 <= x <= 6`
-
+1. `n == grid.length == grid[i].length`
+2. `n == 2^x` 其中 `0 <= x <= 6`
 
 ## 解题思路
 
@@ -234,4 +179,4 @@ as **0**.
 
 ```javascript
 
-```
+```

src/.vuepress/sidebar.ts

@@ -406,6 +406,8 @@ export default sidebar({
           text: "0900-0999",
           collapsible: true,
           children: [
+            "0909",
+            "0918",
             "0921",
             "0931",
             "0945",
@@ -527,6 +529,13 @@ export default sidebar({
             "2696"
           ],
         },
+        {
+          text: "2900-2999",
+          collapsible: true,
+          children: [
+            "2938"
+          ],
+        },
         {
           text: "3300-3399",
           collapsible: true,

src/leetcode/algorithm/dynamic_programming.md

@@ -73,7 +73,7 @@
 | 354 | [俄罗斯套娃信封问题](https://leetcode.com/problems/russian-doll-envelopes) | [[✓]](https://2xiao.github.io/leetcode-js/leetcode/problem/0354) |  [`数组`](/leetcode/outline/tag/array.md) [`二分查找`](/leetcode/outline/tag/binary-search.md) [`动态规划`](/leetcode/outline/tag/dynamic-programming.md) `1+` | <font color=#ff334b>Hard</font> |
 | 53 | [最大子数组和](https://leetcode.com/problems/maximum-subarray) | [[✓]](https://2xiao.github.io/leetcode-js/leetcode/problem/0053) |  [`数组`](/leetcode/outline/tag/array.md) [`分治`](/leetcode/outline/tag/divide-and-conquer.md) [`动态规划`](/leetcode/outline/tag/dynamic-programming.md) | <font color=#ffb800>Medium</font> |
 | 152 | [乘积最大子数组](https://leetcode.com/problems/maximum-product-subarray) | [[✓]](https://2xiao.github.io/leetcode-js/leetcode/problem/0152) |  [`数组`](/leetcode/outline/tag/array.md) [`动态规划`](/leetcode/outline/tag/dynamic-programming.md) | <font color=#ffb800>Medium</font> |
-| 918 | [环形子数组的最大和](https://leetcode.com/problems/maximum-sum-circular-subarray) |  |  [`队列`](/leetcode/outline/tag/queue.md) [`数组`](/leetcode/outline/tag/array.md) [`分治`](/leetcode/outline/tag/divide-and-conquer.md) `2+` | <font color=#ffb800>Medium</font> |
+| 918 | [环形子数组的最大和](https://leetcode.com/problems/maximum-sum-circular-subarray) | [[✓]](https://2xiao.github.io/leetcode-js/leetcode/problem/0918) |  [`队列`](/leetcode/outline/tag/queue.md) [`数组`](/leetcode/outline/tag/array.md) [`分治`](/leetcode/outline/tag/divide-and-conquer.md) `2+` | <font color=#ffb800>Medium</font> |
 | 198 | [打家劫舍](https://leetcode.com/problems/house-robber) | [[✓]](https://2xiao.github.io/leetcode-js/leetcode/problem/0198) |  [`数组`](/leetcode/outline/tag/array.md) [`动态规划`](/leetcode/outline/tag/dynamic-programming.md) | <font color=#ffb800>Medium</font> |
 | 213 | [打家劫舍 II](https://leetcode.com/problems/house-robber-ii) |  |  [`数组`](/leetcode/outline/tag/array.md) [`动态规划`](/leetcode/outline/tag/dynamic-programming.md) | <font color=#ffb800>Medium</font> |
 | 740 | [删除并获得点数](https://leetcode.com/problems/delete-and-earn) |  |  [`数组`](/leetcode/outline/tag/array.md) [`哈希表`](/leetcode/outline/tag/hash-table.md) [`动态规划`](/leetcode/outline/tag/dynamic-programming.md) | <font color=#ffb800>Medium</font> |

src/leetcode/outline/solution_list.md

@@ -1,6 +1,6 @@
 # 1.3 LeetCode 题解
 
-已完成 399 道
+已完成 402 道
 
 <!-- prettier-ignore -->
 | 题号 | 标题 | 题解 | 标签 | 难度 |
@@ -301,6 +301,8 @@
 | 876 | [链表的中间结点](https://leetcode.com/problems/middle-of-the-linked-list) | [[✓]](https://2xiao.github.io/leetcode-js/leetcode/problem/0876) |  [`链表`](/leetcode/outline/tag/linked-list.md) [`双指针`](/leetcode/outline/tag/two-pointers.md) | <font color=#15bd66>Easy</font> |
 | 880 | [索引处的解码字符串](https://leetcode.com/problems/decoded-string-at-index) | [[✓]](https://2xiao.github.io/leetcode-js/leetcode/problem/0880) |  [`栈`](/leetcode/outline/tag/stack.md) [`字符串`](/leetcode/outline/tag/string.md) | <font color=#ffb800>Medium</font> |
 | 889 | [根据前序和后序遍历构造二叉树](https://leetcode.com/problems/construct-binary-tree-from-preorder-and-postorder-traversal) | [[✓]](https://2xiao.github.io/leetcode-js/leetcode/problem/0889) |  [`树`](/leetcode/outline/tag/tree.md) [`数组`](/leetcode/outline/tag/array.md) [`哈希表`](/leetcode/outline/tag/hash-table.md) `2+` | <font color=#ffb800>Medium</font> |
+| 909 | [蛇梯棋](https://leetcode.com/problems/snakes-and-ladders) | [[✓]](https://2xiao.github.io/leetcode-js/leetcode/problem/0909) |  [`广度优先搜索`](/leetcode/outline/tag/breadth-first-search.md) [`数组`](/leetcode/outline/tag/array.md) [`矩阵`](/leetcode/outline/tag/matrix.md) | <font color=#ffb800>Medium</font> |
+| 918 | [环形子数组的最大和](https://leetcode.com/problems/maximum-sum-circular-subarray) | [[✓]](https://2xiao.github.io/leetcode-js/leetcode/problem/0918) |  [`队列`](/leetcode/outline/tag/queue.md) [`数组`](/leetcode/outline/tag/array.md) [`分治`](/leetcode/outline/tag/divide-and-conquer.md) `2+` | <font color=#ffb800>Medium</font> |
 | 921 | [使括号有效的最少添加](https://leetcode.com/problems/minimum-add-to-make-parentheses-valid) | [[✓]](https://2xiao.github.io/leetcode-js/leetcode/problem/0921) |  [`栈`](/leetcode/outline/tag/stack.md) [`贪心`](/leetcode/outline/tag/greedy.md) [`字符串`](/leetcode/outline/tag/string.md) | <font color=#ffb800>Medium</font> |
 | 931 | [下降路径最小和](https://leetcode.com/problems/minimum-falling-path-sum) | [[✓]](https://2xiao.github.io/leetcode-js/leetcode/problem/0931) |  [`数组`](/leetcode/outline/tag/array.md) [`动态规划`](/leetcode/outline/tag/dynamic-programming.md) [`矩阵`](/leetcode/outline/tag/matrix.md) | <font color=#ffb800>Medium</font> |
 | 945 | [使数组唯一的最小增量](https://leetcode.com/problems/minimum-increment-to-make-array-unique) | [[✓]](https://2xiao.github.io/leetcode-js/leetcode/problem/0945) |  [`贪心`](/leetcode/outline/tag/greedy.md) [`数组`](/leetcode/outline/tag/array.md) [`计数`](/leetcode/outline/tag/counting.md) `1+` | <font color=#ffb800>Medium</font> |
@@ -342,6 +344,7 @@
 | 2491 | [划分技能点相等的团队](https://leetcode.com/problems/divide-players-into-teams-of-equal-skill) | [[✓]](https://2xiao.github.io/leetcode-js/leetcode/problem/2491) |  [`数组`](/leetcode/outline/tag/array.md) [`哈希表`](/leetcode/outline/tag/hash-table.md) [`双指针`](/leetcode/outline/tag/two-pointers.md) `1+` | <font color=#ffb800>Medium</font> |
 | 2530 | [执行 K 次操作后的最大分数](https://leetcode.com/problems/maximal-score-after-applying-k-operations) | [[✓]](https://2xiao.github.io/leetcode-js/leetcode/problem/2530) |  [`贪心`](/leetcode/outline/tag/greedy.md) [`数组`](/leetcode/outline/tag/array.md) [`堆（优先队列）`](/leetcode/outline/tag/heap-priority-queue.md) | <font color=#ffb800>Medium</font> |
 | 2696 | [删除子串后的字符串最小长度](https://leetcode.com/problems/minimum-string-length-after-removing-substrings) | [[✓]](https://2xiao.github.io/leetcode-js/leetcode/problem/2696) |  [`栈`](/leetcode/outline/tag/stack.md) [`字符串`](/leetcode/outline/tag/string.md) [`模拟`](/leetcode/outline/tag/simulation.md) | <font color=#15bd66>Easy</font> |
+| 2938 | [区分黑球与白球](https://leetcode.com/problems/separate-black-and-white-balls) | [[✓]](https://2xiao.github.io/leetcode-js/leetcode/problem/2938) |  [`贪心`](/leetcode/outline/tag/greedy.md) [`双指针`](/leetcode/outline/tag/two-pointers.md) [`字符串`](/leetcode/outline/tag/string.md) | <font color=#ffb800>Medium</font> |
 | 3309 | [连接二进制表示可形成的最大数值](https://leetcode.com/problems/maximum-possible-number-by-binary-concatenation) | [[✓]](https://2xiao.github.io/leetcode-js/leetcode/problem/3309) |  [`位运算`](/leetcode/outline/tag/bit-manipulation.md) [`数组`](/leetcode/outline/tag/array.md) [`枚举`](/leetcode/outline/tag/enumeration.md) | <font color=#ffb800>Medium</font> |
 | 3318 | [计算子数组的 x-sum I](https://leetcode.com/problems/find-x-sum-of-all-k-long-subarrays-i) | [[✓]](https://2xiao.github.io/leetcode-js/leetcode/problem/3318) |  | <font color=#15bd66>Easy</font> |
 | 3319 | [第 K 大的完美二叉子树的大小](https://leetcode.com/problems/k-th-largest-perfect-subtree-size-in-binary-tree) | [[✓]](https://2xiao.github.io/leetcode-js/leetcode/problem/3319) |  | <font color=#ffb800>Medium</font> |