对所有节点都进行判断1 检查,即可知道图中是否存在环。 View Code 210. Course Schedule II There are a total ofncourses you have to take, labeled from0ton - 1. Some courses may have prerequisites, for example to take course 0 you have to first take course 1, which is expressed as a pair:...
boolLeetCode::canFinish(intnumCourses, vector<pair<int,int>>&prerequisites){if(numCourses <1)returntrue;//没有课程if(!prerequisites.size())returntrue;//没有依赖关系vector<vector<int>>courses(numCourses);//第i个课程依赖于courses[i]里的课程for(size_t i =0; i < prerequisites.size(); i+...
题目地址:https://leetcode.com/problems/course-schedule/description/ 题目描述: There are a total of n courses you have to take, labeled from0ton-1. Some courses may have prerequisites, for example to take course 0 you have to first take course 1, which is expressed as a pair:[0,1] G...
建议和leetcode 210. Course Schedule II 拓扑排序 + HashSet和leetcode 630. Course Schedule III 课程调度 + 贪心算法 一起学习 需要注意的是,由于这道题更新了测试用例所以原先的代码可能出现问题,情况是这样的,记录后继结点要使用vector,不要使用set,因为假如存在(1,9)和(1,9)多次出现,这样就会出现问题,所...
[LeetCode]CourseSchedule书影博客[LeetCode]CourseSchedule 书影博客 题目描述: There are a total of n courses you have to take, labeled from 0 to n - 1. Some courses may have prerequisites, for example to take course 0 you have to first take course 1, which is expressed as a pair: [0...
Can you solve this real interview question? Course Schedule IV - There are a total of numCourses courses you have to take, labeled from 0 to numCourses - 1. You are given an array prerequisites where prerequisites[i] = [ai, bi] indicates that you must ta
现在你总共有numCourses门课需要选,记为0到numCourses - 1。给你一个数组prerequisites,其中prerequisites[i] = [ai, bi],表示在选修课程ai前必须先选修bi。 例如,想要学习课程0,你需要先完成课程1,我们用一个匹配来表示:[0,1]。 返回你为了学完所有课程所安排的学习顺序。可能会有多个正确的顺序,你只要返回...
Some courses may have prerequisites, for example to take course 0 you have to first take course 1, which is expressed as a pair:[0,1] Given the total number of courses and a list of prerequisitepairs, return the ordering of courses you should take to finish all courses. ...
207. Course Schedule 题目描述(中等难度) 给定n组先修课的关系,[m,n]代表在上m这门课之前必须先上n这门课。输出能否成功上完所有课。 解法一 把所有的关系可以看做图的边,所有的边构成了一个有向图。 对于[ [1,3],[1,4], [2,4],[3,5],...
若该相邻节点-1后入度为0,则重新加入队列中。 最后判断一下是否所有节点都经过了该流程,若处理节点个数没有达到numCourses返回空数组即可。 复杂度分析 时间复杂度: O(N): 取决于处理的节点个数。 空间复杂度: O(N): 取决于处理的节点个数。 代码 class Solution { class Node { int in; int value; ...