https://leetcode.com/problems/race-car/description/ 1. BFS剪枝 0<=current position<=2*target.为什么2*target有点不太明白 class Solution { public: ]; struct Node{ int pos; int speed; int step; Node(int p,int s,int ss){ pos=p; speed=s; step=ss; } }; int racecar(i…

原题链接在这里:https://leetcode.com/problems/race-car/ 题目: Your car starts at position 0 and speed +1 on an infinite number line.  (Your car can go into negative positions.) Your car drives automatically according to a sequence of instructions A (accelerate…

Your car starts at position 0 and speed +1 on an infinite number line.  (Your car can go into negative positions.) Your car drives automatically according to a sequence of instructions A (accelerate) and R (reverse). When you get an instruction "A&qu…

All LeetCode Questions List(Part of Answers, still updating) 题目汇总及部分答案(持续更新中) Leetcode problems classified by company 题目按公司分类(Last updated: October 2, 2017) .   Top Interview Questions # Title Difficulty Acceptance 1 Two Sum Medium 17.70% 2 Add Two N…

# Title Solution Acceptance Difficulty Frequency     4 Median of Two Sorted Arrays       27.2% Hard     10 Regular Expression Matching       25.6% Hard     23 Merge k Sorted Lists       35.8% Hard     25 Reverse Nodes in k-Group       37.7% Hard    …

Your car starts at position 0 and speed +1 on an infinite number line.  (Your car can go into negative positions.) Your car drives automatically according to a sequence of instructions A (accelerate) and R (reverse). When you get an instruction "A&qu…

题意:给一个用序列堆成的三角形,第n层的元素个数为n,从顶往下,每个元素可以选择与自己最近的两个下层元素往下走,类似一棵二叉树,求最短路. [], [,4], [6,,7], [4,,8,3] 注意:这里可以2->3>5>1,也可以2->4>5->1,隔层相邻就可以走. 思路:可以从下往上走,也可以从上往下走.都是O(n)的空间,平方阶的复杂度. 从下往上可能更简洁,因为比较到最后只有一个元素,就是为答案了,速度自然也就快,每遍历一层就有1个被淘汰. 然而我一开始想到的…

There are N network nodes, labelled 1 to N. Given times, a list of travel times as directed edges times[i] = (u, v, w), where u is the source node, v is the target node, and w is the time it takes for a signal to travel from source to target. Now, we…

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. 思路:此题和前面几个机器人的题很相像.仅仅是变化了一点.详细代码和…

链接:https://leetcode.com/tag/heap/ [23] Merge k Sorted Lists [215] Kth Largest Element in an Array (无序数组中最小/大的K个数)(2018年11月30日第一次复习) 给了一个无序数组,可能有重复数字,找到第 k 个最大的元素并且返回这个元素值. 题解:直接用直接用个堆保存数组中最大的 K 个数.时间复杂度是 O(NlogK). //时间复杂度是 O(NlogK), 用堆辅助. class Solut…