feat: 2213. Longest Substring of One Repeating Character : 线段树

Author: upupming

leetcode/残酷刷题/2213. Longest Substring of One Repeating Character.ts

@@ -0,0 +1,97 @@
+function longestRepeating (s: string, queryCharacters: string, queryIndices: number[]): number[] {
+  const tree = new SegmentTree(0, s.length)
+  for (let i = 0; i < s.length; i++) {
+    tree.modify(i, s[i])
+  }
+  const ans = []
+  for (let i = 0; i < queryCharacters.length; i++) {
+    tree.modify(queryIndices[i], queryCharacters[i])
+    ans.push(Math.max(...tree.query(0, s.length)))
+  }
+  return ans
+};
+
+export declare const a: 1
+
+class Node {
+  start: number
+  end: number
+  maxLen: number[]
+  leftMaxLen: number[]
+  rightMaxLen: number[]
+  left: null | Node = null
+  right: null | Node = null
+  constructor (start: number, end: number) {
+    this.start = start
+    this.end = end
+    this.maxLen = Array(26).fill(0)
+    this.leftMaxLen = Array(26).fill(0)
+    this.rightMaxLen = Array(26).fill(0)
+  }
+}
+
+// https://www.acwing.com/activity/content/code/content/167900/
+class SegmentTree {
+  root: Node
+  constructor (start: number, end: number) {
+    this.root = new Node(start, end)
+  }
+
+  modify (pos: number, char: string) {
+    this.modifyNode(this.root, pos, char)
+  }
+
+  modifyNode (node: Node, pos: number, char: string) {
+    if (node.start === pos && node.end === pos) {
+      for (let i = 0; i < 26; i++) {
+        node.leftMaxLen[i] = node.rightMaxLen[i] = node.maxLen[i] = char === (String.fromCharCode('a'.charCodeAt(0) + i)) ? 1 : 0
+      }
+    } else {
+      this.pushdown(node)
+      if (pos <= node.left!.end) this.modifyNode(node.left!, pos, char)
+      if (pos >= node.right!.start) this.modifyNode(node.right!, pos, char)
+      this.pushup(node)
+    }
+  }
+
+  // 这里 pushdown 的作用只是动态创建新节点
+  pushdown (node: Node) {
+    const mid = node.start + node.end >> 1
+    node.left ??= new Node(node.start, mid)
+    node.right ??= new Node(mid + 1, node.end)
+  }
+
+  pushup (node: Node) {
+    for (let i = 0; i < 26; i++) {
+      node.leftMaxLen[i] = node.left!.leftMaxLen[i]
+      if (node.left!.leftMaxLen[i] === node.left!.end - node.left!.start + 1) {
+        node.leftMaxLen[i] = node.left!.leftMaxLen[i] + node.right!.leftMaxLen[i]
+      }
+
+      node.rightMaxLen[i] = node.right!.rightMaxLen[i]
+      if (node.right!.rightMaxLen[i] === node.right!.end - node.right!.start + 1) {
+        node.rightMaxLen[i] = node.right!.rightMaxLen[i] + node.left!.rightMaxLen[i]
+      }
+
+      node.maxLen[i] = Math.max(node.left!.maxLen[i], node.right!.maxLen[i], node.left!.rightMaxLen[i] + node.right!.leftMaxLen[i])
+    }
+  }
+
+  query (start: number, end: number) {
+    return this.queryNode(this.root, start, end)
+  }
+
+  arrayAdd (a: number[], b: number[]) {
+    for (let i = 0; i < a.length; i++) a[i] += b[i]
+  }
+
+  queryNode (node: Node, start: number, end: number) {
+    if (start <= node.start && end >= node.end) return node.maxLen
+
+    this.pushdown(node)
+    const sum = Array(26)
+    if (start <= node.left!.end) this.arrayAdd(sum, this.queryNode(node.left!, start, end))
+    if (end >= node.right!.start) this.arrayAdd(sum, this.queryNode(node.right!, start, end))
+    return sum
+  }
+}

leetcode/残酷刷题/README.md

@@ -281,6 +281,7 @@
 ## 线段树
 
 - 715. Range Module
+- 2213. Longest Substring of One Repeating Character
 
 ## Links
 

template-typescript.md

@@ -15,6 +15,8 @@
   - [拓扑排序](#拓扑排序)
   - [字符串哈希](#字符串哈希)
   - [线段树](#线段树)
+    - [单点修改](#单点修改)
+    - [区间修改](#区间修改)
 
 ## 输入
 
@@ -265,6 +267,100 @@ const hash = (i, j) => {
 
 ## 线段树
 
+统一使用动态开点线段树。
+
+### 单点修改
+
+> https://leetcode.com/problems/longest-substring-of-one-repeating-character/
+
+```ts
+class Node {
+  start: number
+  end: number
+  maxLen: number[]
+  leftMaxLen: number[]
+  rightMaxLen: number[]
+  left: null | Node = null
+  right: null | Node = null
+  constructor (start: number, end: number) {
+    this.start = start
+    this.end = end
+    this.maxLen = Array(26).fill(0)
+    this.leftMaxLen = Array(26).fill(0)
+    this.rightMaxLen = Array(26).fill(0)
+  }
+}
+
+// https://www.acwing.com/activity/content/code/content/167900/
+class SegmentTree {
+  root: Node
+  constructor (start: number, end: number) {
+    this.root = new Node(start, end)
+  }
+
+  modify (pos: number, char: string) {
+    this.modifyNode(this.root, pos, char)
+  }
+
+  modifyNode (node: Node, pos: number, char: string) {
+    if (node.start === pos && node.end === pos) {
+      for (let i = 0; i < 26; i++) {
+        node.leftMaxLen[i] = node.rightMaxLen[i] = node.maxLen[i] = char === (String.fromCharCode('a'.charCodeAt(0) + i)) ? 1 : 0
+      }
+    } else {
+      this.pushdown(node)
+      if (pos <= node.left!.end) this.modifyNode(node.left!, pos, char)
+      if (pos >= node.right!.start) this.modifyNode(node.right!, pos, char)
+      this.pushup(node)
+    }
+  }
+
+  // 这里 pushdown 的作用只是动态创建新节点
+  pushdown (node: Node) {
+    const mid = node.start + node.end >> 1
+    node.left ??= new Node(node.start, mid)
+    node.right ??= new Node(mid + 1, node.end)
+  }
+
+  pushup (node: Node) {
+    for (let i = 0; i < 26; i++) {
+      node.leftMaxLen[i] = node.left!.leftMaxLen[i]
+      if (node.left!.leftMaxLen[i] === node.left!.end - node.left!.start + 1) {
+        node.leftMaxLen[i] = node.left!.leftMaxLen[i] + node.right!.leftMaxLen[i]
+      }
+
+      node.rightMaxLen[i] = node.right!.rightMaxLen[i]
+      if (node.right!.rightMaxLen[i] === node.right!.end - node.right!.start + 1) {
+        node.rightMaxLen[i] = node.right!.rightMaxLen[i] + node.left!.rightMaxLen[i]
+      }
+
+      node.maxLen[i] = Math.max(node.left!.maxLen[i], node.right!.maxLen[i], node.left!.rightMaxLen[i] + node.right!.leftMaxLen[i])
+    }
+  }
+
+  query (start: number, end: number) {
+    return this.queryNode(this.root, start, end)
+  }
+
+  arrayAdd (a: number[], b: number[]) {
+    for (let i = 0; i < a.length; i++) a[i] += b[i]
+  }
+
+  queryNode (node: Node, start: number, end: number) {
+    if (start <= node.start && end >= node.end) return node.maxLen
+
+    this.pushdown(node)
+    const sum = Array(26)
+    if (start <= node.left!.end) this.arrayAdd(sum, this.queryNode(node.left!, start, end))
+    if (end >= node.right!.start) this.arrayAdd(sum, this.queryNode(node.right!, start, end))
+    return sum
+  }
+}
+
+```
+
+### 区间修改
+
 ```ts
 enum Tracked {
   TRUE = 'TRUE',