文章目錄引言查找一個數尋找最左邊的滿足條件的值面試題 08.03. 魔術索引尋找最右邊的滿足條件的值尋找最左插入位置35. 搜索插入位置34. 在排序數組中查找元素的第一個和最后一個位置尋找最右插入位置的情況局部有序(先降后升或先升后降)33. 搜索旋轉排序數組81. 搜索旋轉排

? Given preorder and inorder traversal of a tree, construct the binary tree. Note:You may assume that duplicates do not exist in the tree. ? leetcode 最長公共子序列？這道題要求用先序和中序遍歷來建立二叉樹，跟之前那道Construct Binary Tree from Inorde

傳送門 Description Given an integer (signed 32 bits), write a function to check whether it is a power of 4. Example:Given num = 16, return true. Given num = 5, return false. Follow up: Could you solve it without loops/recursion? 思路 題意：不

隨便寫下暴力就過了，美版也是 class ProductOfNumbers {vector<int>nums; public:ProductOfNumbers() {}void add(int num) {nums.push_back(num);}int getProduct(int k) {typedef long long ll;ll res = 1;for(int i = nums.size() - k; i < nums.

雙指針 class Solution { public:vector<vector<int>> threeSum(vector<int>& nums) {vector<vector<int>>res;if(nums.size() == 0){return res;}sort(nums.begin(), nums.end());for(int i = 0; i < nums.size(); i+

1. 括號匹配 20. Valid Parentheses 堆棧版： class Solution(object):def isValid(self, s):""":type s: str:rtype: bool"""stack = []para_map = {')':'(', ']':'[', '}':'{'}for

題目： ? Given a?m?x?n?grid filled with non-negative numbers, find a path from top left to bottom right which?minimizes?the sum of all numbers along its path. Note:?You can only move either down or right at any point in time. 題意從左上到右下，

1.面試先說出最簡單的方法，然后在繼續優化，不要想復雜，先暴力解決 2.理解問題，和面試交流題意 3.注意邊界條件 4.不著急 一、二分 leetcode 100題？?33.搜索旋轉排序數組 153. 尋找旋轉排序數組中的最小值 用二分法求方程的近似解的方法 leetcode

題目： A message containing letters from?A-Z?is being encoded to numbers using the following mapping: 'A' -> 1 'B' -> 2 ... 'Z' -> 26 Given an encoded message containing digits, determine the total number of ways to

題目描述： Given an integer, write a function to determine if it is a power of two. ? 要完成的函數： bool isPowerOfTwo(int n)? ? 說明： 1、給定一個int型整數，判斷它是不是2的冪。首先我們可以確定負數和0都不是2的冪。1是2的0次冪。 2、如