add: 算法

Eric-art-coder · Eric-art-coder · commit 5aecd2f2a9d9 · 2023-10-18T20:32:28.000+08:00
diff --git a/labuladuo/10.正则表达式匹配.js b/labuladuo/10.正则表达式匹配.js
@@ -0,0 +1,47 @@
+/*
+ * @lc app=leetcode.cn id=10 lang=javascript
+ *
+ * [10] 正则表达式匹配
+ */
+
+// @lc code=start
+/**
+ * @param {string} s
+ * @param {string} p
+ * @return {boolean}
+ */
+var isMatch = function(s, p) {
+  let m = s.length, n = p.length;
+  // 备忘录
+  let memo = new Array(m + 1);
+  for (let i = 0; i < memo.length; i++) {
+      memo[i] = new Array(n + 1).fill(-1);
+  }
+
+  return dp(0, 0);
+
+  /* 计算 p[j..] 是否匹配 s[i..] */
+  function dp(i, j) {
+      // 查备忘录，防止重复计算
+      if (memo[i][j] !== -1) {
+          return memo[i][j];
+      }
+      let res = false;
+      // base case
+      if (j === n) {
+          res = i === m;
+      } else {
+          let firstMatch = i < m && (p[j] === s[i] || p[j] === '.');
+          if (j + 1 < n && p[j + 1] === '*') {
+              res = dp(i, j + 2) || (firstMatch && dp(i + 1, j));
+          } else {
+              res = firstMatch && dp(i + 1, j + 1);
+          }
+      }
+      // 将当前结果记入备忘录
+      memo[i][j] = res;
+      return res;
+  }
+};
+// @lc code=end
+
diff --git a/labuladuo/11.盛最多水的容器.js b/labuladuo/11.盛最多水的容器.js
@@ -0,0 +1,28 @@
+/*
+ * @lc app=leetcode.cn id=11 lang=javascript
+ *
+ * [11] 盛最多水的容器
+ */
+
+// @lc code=start
+/**
+ * @param {number[]} height
+ * @return {number}
+ */
+var maxArea = function(height) {
+  // 这个就是接雨水的套路
+  let left = 0, right = height.length - 1
+  let res = 0
+  while(left < right) {
+    // 和接雨水差不多，接雨水是需要对比左边heigh和右边height
+    res = Math.max(res, Math.min(height[left], height[right]) * (right - left))
+    if(height[left] < height[right]) {
+      left++
+    }else {
+      right--
+    }
+  }
+  return res
+};
+// @lc code=end
+
diff --git a/labuladuo/12.整数转罗马数字.js b/labuladuo/12.整数转罗马数字.js
@@ -0,0 +1,19 @@
+/*
+ * @lc app=leetcode.cn id=12 lang=javascript
+ *
+ * [12] 整数转罗马数字
+ */
+
+// @lc code=start
+/**
+ * @param {number} num
+ * @return {string}
+ */
+var intToRoman = function(num) {
+  var Q = ["", "M", "MM", "MMM"];
+  var B = ["", "C", "CC", "CCC", "CD", "D", "DC", "DCC", "DCCC", "CM"];
+  var S = ["", "X", "XX", "XXX", "XL", "L", "LX", "LXX", "LXXX", "XC"];
+  var G = ["", "I", "II", "III", "IV", "V", "VI", "VII", "VIII", "IX"];
+  return Q[Math.floor(num/1000)] + B[Math.floor((num%1000)/100)] + S[Math.floor((num%100)/10)] + G[num%10];
+};
+// @lc code=end
diff --git a/labuladuo/13.罗马数字转整数.js b/labuladuo/13.罗马数字转整数.js
@@ -0,0 +1,41 @@
+/*
+ * @lc app=leetcode.cn id=13 lang=javascript
+ *
+ * [13] 罗马数字转整数
+ */
+
+// @lc code=start
+/**
+ * @param {string} s
+ * @return {number}
+ */
+var romanToInt = function(s) {
+  const map = {
+    I: 1,
+    IV: 4,
+    V: 5,
+    IX: 9,
+    X: 10,
+    XL: 40,
+    L: 50,
+    XC: 90,
+    C: 100,
+    CD: 400,
+    D: 500,
+    CM: 900,
+    M: 1000
+  }
+  let ans = 0
+  for (let i = 0; i < s.length;) {
+    if((i + 1 < s.length) && map[s.substring(i, i+2)]) {
+      ans += map[s.substring(i, i+2)]
+      i += 2
+    }else {
+      ans += map[s.substring(i, i+1)]
+      i++
+    }    
+  }
+  return ans
+};
+// @lc code=end
+
diff --git a/labuladuo/2.两数相加.js b/labuladuo/2.两数相加.js
@@ -0,0 +1,46 @@
+/*
+ * @lc app=leetcode.cn id=2 lang=javascript
+ *
+ * [2] 两数相加
+ */
+
+// @lc code=start
+/**
+ * Definition for singly-linked list.
+ * function ListNode(val, next) {
+ *     this.val = (val===undefined ? 0 : val)
+ *     this.next = (next===undefined ? null : next)
+ * }
+ */
+/**
+ * @param {ListNode} l1
+ * @param {ListNode} l2
+ * @return {ListNode}
+ */
+var addTwoNumbers = function(l1, l2) {
+  let p1 = l1, p2 = l2;
+  let dummy = new ListNode(-1)
+  let p = dummy
+  let carry = 0
+  while(p1 != null || p2 != null || carry > 0) {
+    // 处理推进和处理
+    let val = carry
+    if(p1 != null) {
+      val += p1.val
+      p1 = p1.next
+    }
+    if(p2 != null) {
+      val += p2.val
+      p2 = p2.next
+    }
+    // 处理进位情况
+    carry = Math.floor(val / 10)
+    val = val % 10
+    // 构建新的节点
+    p.next = new ListNode(val)
+    p = p.next
+  }
+  return dummy.next
+};
+// @lc code=end
+
diff --git a/labuladuo/4.寻找两个正序数组的中位数.js b/labuladuo/4.寻找两个正序数组的中位数.js
@@ -0,0 +1,17 @@
+/*
+ * @lc app=leetcode.cn id=4 lang=javascript
+ *
+ * [4] 寻找两个正序数组的中位数
+ */
+
+// @lc code=start
+/**
+ * @param {number[]} nums1
+ * @param {number[]} nums2
+ * @return {number}
+ */
+var findMedianSortedArrays = function(nums1, nums2) {
+  
+};
+// @lc code=end
+
diff --git a/labuladuo/46.全排列.js b/labuladuo/46.全排列.js
@@ -0,0 +1,16 @@
+/*
+ * @lc app=leetcode.cn id=46 lang=javascript
+ *
+ * [46] 全排列
+ */
+
+// @lc code=start
+/**
+ * @param {number[]} nums
+ * @return {number[][]}
+ */
+var permute = function(nums) {
+
+};
+// @lc code=end
+
diff --git a/labuladuo/6.n-字形变换.js b/labuladuo/6.n-字形变换.js
@@ -0,0 +1,30 @@
+/*
+ * @lc app=leetcode.cn id=6 lang=javascript
+ *
+ * [6] N 字形变换
+ */
+
+// @lc code=start
+/**
+ * @param {string} s
+ * @param {number} numRows
+ * @return {string}
+ */
+var convert = function(s, numRows) {
+  if(numRows == 1) return s
+
+  const len = Math.min(s.length, numRows)
+  const rows = new Array(len).fill('')
+  let loc = 0, down = false
+  // 记得那个动画就好，上下轮动，其他的都是为这个做准备
+  for (const c of s) {
+    rows[loc] += c
+    if(loc == 0 || loc == numRows - 1) {
+      down = !down
+    }
+    loc += down ? 1 : -1
+  }
+  return rows.join('')
+};
+// @lc code=end
+
diff --git a/labuladuo/7.整数反转.js b/labuladuo/7.整数反转.js
@@ -0,0 +1,28 @@
+/*
+ * @lc app=leetcode.cn id=7 lang=javascript
+ *
+ * [7] 整数反转
+ */
+
+// @lc code=start
+/**
+ * @param {number} x
+ * @return {number}
+ */
+var reverse = function(x) {
+  let isPos = true 
+  let y = x
+  // 处理负值
+  if(x < 0) {
+    y = Math.abs(x)
+    isPos = false
+  }
+  // 核心计算，我不会位运算
+  let numRes = Number(y.toString().split('').reverse().join(''))
+  // 数字大小限制
+  let res = isPos === false ?  -1 * numRes : numRes
+  if(res > Math.pow(2, 31) - 1 || res < Math.pow(-2, 31)) return 0;
+  return res
+};
+// @lc code=end
+
diff --git a/labuladuo/8.字符串转换整数-atoi.js b/labuladuo/8.字符串转换整数-atoi.js
@@ -0,0 +1,30 @@
+/*
+ * @lc app=leetcode.cn id=8 lang=javascript
+ *
+ * [8] 字符串转换整数 (atoi)
+ */
+
+// @lc code=start
+/**
+ * @param {string} s
+ * @return {number}
+ */
+var myAtoi = function(str) {
+  const number = parseInt(str, 10);
+
+  if(isNaN(number)) {
+      return 0;
+  } else if (number < -(2**31) || number > 2**31-1) {
+      return number < -(2**31) ? -(2**31) : 2**31-1;
+  } else {
+      return number;
+  }
+};
+// @lc code=end
+
+// 另外的思路
+/*
+let res = str.trim().match(/^(\-|\+)?\d+/g)
+  return res ? Math.max(Math.min(Number(res[0]),2**31-1),-(2**31)) : 0
+*/
+
diff --git a/labuladuo/9.回文数.js b/labuladuo/9.回文数.js
@@ -0,0 +1,21 @@
+/*
+ * @lc app=leetcode.cn id=9 lang=javascript
+ *
+ * [9] 回文数
+ */
+
+// @lc code=start
+/**
+ * @param {number} x
+ * @return {boolean}
+ */
+var isPalindrome = function(x) {
+  if(x < 0) return false
+  if(x < -(2**31) || x > 2**31) return false
+  // 里面toString、reverse、join('')都是容易错的点 
+  let _x = x.toString().split('').reverse().join('')
+  console.log('----', _x)
+  return _x == x
+};
+// @lc code=end
+
diff --git a/专项/万级别数据渲染问题/分片渲染.js b/专项/万级别数据渲染问题/分片渲染.js
@@ -0,0 +1,23 @@
+// 实现思路：每几十毫秒渲染20个，这个间隔时间可以使用requestAnimationFrame
+// 以下为简化代码
+setTimeout(() => {
+  const total = 10000
+  const once = 20
+  const loopCount = total / once
+  let countOfRender = 0
+  function add() {
+    // 片段Fragment
+    const fragment = document.createDocumentFragment()
+    for (let i = 0; i < once; i++) {
+      // ...
+      fragment.appendChild(li);
+    }
+    countOfRender++
+    loop()
+  }
+  function loop() {
+    if(countOfRender < loopCount) {
+      window.requestAnimationFrame(add)
+    }
+  }
+})
