Merge branch 'youngyangyang04:master' into master

This commit is contained in:
SianXiaoCHN
2022-03-19 10:57:17 -05:00
committed by GitHub
5 changed files with 30 additions and 20 deletions

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@ -174,6 +174,7 @@ const maxSubArray = nums => {
// 数组长度dp初始化 // 数组长度dp初始化
const len = nums.length; const len = nums.length;
let dp = new Array(len).fill(0); let dp = new Array(len).fill(0);
dp[0] = nums[0];
// 最大值初始化为dp[0] // 最大值初始化为dp[0]
let max = dp[0]; let max = dp[0];
for (let i = 1; i < len; i++) { for (let i = 1; i < len; i++) {

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@ -89,27 +89,26 @@ class Solution {
private: private:
bool backtracking (const string& s, bool backtracking (const string& s,
const unordered_set<string>& wordSet, const unordered_set<string>& wordSet,
vector<int>& memory, vector<bool>& memory,
int startIndex) { int startIndex) {
if (startIndex >= s.size()) { if (startIndex >= s.size()) {
return true; return true;
} }
// 如果memory[startIndex]不是初始值了直接使用memory[startIndex]的结果 // 如果memory[startIndex]不是初始值了直接使用memory[startIndex]的结果
if (memory[startIndex] != -1) return memory[startIndex]; if (!memory[startIndex]) return memory[startIndex];
for (int i = startIndex; i < s.size(); i++) { for (int i = startIndex; i < s.size(); i++) {
string word = s.substr(startIndex, i - startIndex + 1); string word = s.substr(startIndex, i - startIndex + 1);
if (wordSet.find(word) != wordSet.end() && backtracking(s, wordSet, memory, i + 1)) { if (wordSet.find(word) != wordSet.end() && backtracking(s, wordSet, memory, i + 1)) {
memory[startIndex] = 1; // 记录以startIndex开始的子串是可以被拆分的
return true; return true;
} }
} }
memory[startIndex] = 0; // 记录以startIndex开始的子串是不可以被拆分的 memory[startIndex] = false; // 记录以startIndex开始的子串是不可以被拆分的
return false; return false;
} }
public: public:
bool wordBreak(string s, vector<string>& wordDict) { bool wordBreak(string s, vector<string>& wordDict) {
unordered_set<string> wordSet(wordDict.begin(), wordDict.end()); unordered_set<string> wordSet(wordDict.begin(), wordDict.end());
vector<int> memory(s.size(), -1); // -1 表示初始化状态 vector<bool> memory(s.size(), 1); // -1 表示初始化状态
return backtracking(s, wordSet, memory, 0); return backtracking(s, wordSet, memory, 0);
} }
}; };

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@ -325,6 +325,20 @@ var lowestCommonAncestor = function(root, p, q) {
}; };
``` ```
## TypeScript
```typescript
function lowestCommonAncestor(root: TreeNode | null, p: TreeNode | null, q: TreeNode | null): TreeNode | null {
if (root === null || root === p || root === q) return root;
const left = lowestCommonAncestor(root.left, p, q);
const right = lowestCommonAncestor(root.right, p, q);
if (left !== null && right !== null) return root;
if (left !== null) return left;
if (right !== null) return right;
return null;
};
```
----------------------- -----------------------

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@ -37,7 +37,7 @@
1. dp[i]的定义 1. dp[i]的定义
**dp[i]表示i之前包括i的最长上升子序列的长度** **dp[i]表示i之前包括i的以nums[i]结尾最长上升子序列的长度**
2. 状态转移方程 2. 状态转移方程

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@ -148,23 +148,19 @@ java版本1中创建了String数组多次使用Integer.parseInt了方法
版本2 版本2
class Solution { class Solution {
public int monotoneIncreasingDigits(int n) { public int monotoneIncreasingDigits(int n) {
if (n==0)return 0; String s = String.valueOf(n);
char[] chars= Integer.toString(n).toCharArray(); char[] chars = s.toCharArray();
int start=Integer.MAX_VALUE;//start初始值设为最大值这是为了防止当数字本身是单调递增时没有一位数字需要改成9的情况 int start = s.length();
for (int i=chars.length-1;i>0;i--){ for (int i = s.length() - 2; i >= 0; i--) {
if (chars[i]<chars[i-1]){ if (chars[i] > chars[i + 1]) {
chars[i-1]--; chars[i]--;
start=i; start = i+1;
} }
} }
StringBuilder res=new StringBuilder(); for (int i = start; i < s.length(); i++) {
for (int i=0;i<chars.length;i++){ chars[i] = '9';
if (chars[i]=='0'&&i==0)continue;//防止出现09这样的情况
if (i>=start){
res.append('9');
}else res.append(chars[i]);
} }
return Integer.parseInt(res.toString()); return Integer.parseInt(String.valueOf(chars));
} }
} }
``` ```