题目 Total Accepted: 47928 Total Submissions: 148011 Difficulty: Medium 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…
之所以将这三道题放在一起,是因为这三道题非常类似. 1. Minimum Path Sum 题目链接 题目要求: 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 righ…
problem: 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. Hide Tags Array Dynamic…
题目 Given a string S and a string T, find the minimum window in S which will contain all the characters in T in complexity O(n). For example, S = "ADOBECODEBANC" T = "ABC" Minimum window is "BANC". Note: If there is no such wi…
题目 Given an absolute path for a file (Unix-style), simplify it. For example, path = "/home/", => "/home" path = "/a/./b/../../c/", => "/c" click to show corner cases. Corner Cases: Did you consider the case wh…
题目 Given a binary tree, find its minimum depth. The minimum depth is the number of nodes along the shortest path from the root node down to the nearest leaf node. 分析 求二叉树的最小深度:根节点到最近叶子节点的路径长度. 同样采用递归的思想: 当根节点为空,返回0: 当根节点为唯一的二叉树节点时,返回1: 否则,求解并返回 最小(非空…
Unique Paths https://oj.leetcode.com/problems/unique-paths/ A robot is located at the top-left corner of a m x n grid (marked 'Start' in the diagram below). The robot can only move either down or right at any point in time. The robot is trying to rea…
题目 Given a binary tree and a sum, find all root-to-leaf paths where each path's sum equals the given sum. For example: Given the below binary tree and sum = 22, 分析 本题目与上一题LeetCode(112) Path Sum虽然类型相同,但是需要在以前的基础上,多做处理一些: 与Path Sum相比,本题是求出路径,所以,在找到满足的路…
Minimum Path Sum 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. 解题思路: 典型的动态规划.开辟…
题目描述: 题目链接:64 Minimum Path Sum 问题是要求在一个全为正整数的 m X n 的矩阵中, 取一条从左上为起点, 走到右下为重点的路径, (前进方向只能向左或者向右),求一条所经过元素和最小的一条路径. 其实,题目已经给出了提示:, 动态规划应该是最直接的解法之一. 这边我们了解到, 问题中只允许走到的每个点右移或者下移,这就意味着从起点开始, 都有两种后继路径(最后一行和最后一列除外),以此类推, 得到所有路径,然后取其中路径和虽小的值,就可以得到结果了. 但是!我们仔…
Minimum Path Sum 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. 还是DP问题,给定一个m*n的二…
引言 二维动态规划中最常见的是棋盘型二维动态规划. 即 func(i, j) 往往只和 func(i-1, j-1), func(i-1, j) 以及 func(i, j-1) 有关 这种情况下,时间复杂度 O(n*n),空间复杂度往往可以优化为O(n) 例题 1 Minimum Path Sum Given a m x n grid filled with non-negative numbers, find a path from top left to bottom right whi…
Minimum Path Sum 题解 原创文章,拒绝转载 题目来源:https://leetcode.com/problems/minimum-path-sum/description/ Description 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…
题目 Follow up for "Find Minimum in Rotated Sorted Array": What if duplicates are allowed? Would this affect the run-time complexity? How and why? Suppose a sorted array is rotated at some pivot unknown to you beforehand. (i.e., 0 1 2 4 5 6 7 migh…
Minimum Path Sum 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. 动态规划即可,与Unique…
Minimum Path Sum 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. SOLUTION 1: 相当基础…
题目 Given a triangle, find the minimum path sum from top to bottom. Each step you may move to adjacent numbers on the row below. For example, given the following triangle The minimum path sum from top to bottom is 11 (i.e., 2 + 3 + 5 + 1 = 11). 分析 本题类…
题目 Say you have an array for which the ith element is the price of a given stock on day i. Design an algorithm to find the maximum profit. You may complete as many transactions as you like (ie, buy one and sell one share of the stock multiple times).…
题目 Follow up for H-Index: What if the citations array is sorted in ascending order? Could you optimize your algorithm? 分析 同LeetCode(274)H-Index第二个版本,给定引用数量序列为递增的:这就省略了我们的第一个排序步骤: O(n)的时间复杂度,遍历一次即可. AC代码 class Solution { public: int hIndex(vector<int>…
题目 Given an array of integers, find out whether there are two distinct indices i and j in the array such that the difference between nums[i] and nums[j] is at most t and the difference between i and j is at most k. 分析 题目描述:给定一个整数序列,查找是否存在两个下标分别为i和j的元…
题目 Given a binary tree struct TreeLinkNode { TreeLinkNode *left; TreeLinkNode *right; TreeLinkNode *next; } Populate each next pointer to point to its next right node. If there is no next right node, the next pointer should be set to NULL. Initially,…
题目 Given a binary tree, return the bottom-up level order traversal of its nodes' values. (ie, from left to right, level by level from leaf to root). For example: Given binary tree {3,9,20,#,#,15,7}, return its bottom-up level order traversal as: 分析 与…
题目 There are two sorted arrays nums1 and nums2 of size m and n respectively. Find the median of the two sorted arrays. The overall run time complexity should be O(log (m+n)). 分析 给定两个有序序列,要求两个序列综合后的中位数.关键:算法复杂度T(n)=O(log(m+n)) 该问题的关键就在于复杂度的限制,有了这个限制,就…
