In a directed graph, we start at some node and every turn, walk along a directed edge of the graph.  If we reach a node that is terminal (that is, it has no outgoing directed edges), we stop. Now, say our starting node is eventually safe if and only…

[LeetCode]802. Find Eventual Safe States 解题报告(Python) 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 题目地址:https://leetcode.com/problems/find-eventual-safe-states/description/ 题目描述: In a directed graph, we start at some node and every turn, w…

https://leetcode.com/problems/find-eventual-safe-states/description/ class Solution { public: vector<bool> visited; vector<int> mem; // -1 unknown, 0 unsafe, 1 safe. int n; vector<int> eventualSafeNodes(vector<vector<int>>&am…

原题链接在这里:https://leetcode.com/problems/find-eventual-safe-states/ 题目: In a directed graph, we start at some node and every turn, walk along a directed edge of the graph.  If we reach a node that is terminal (that is, it has no outgoing directed edges)…

In a directed graph, we start at some node and every turn, walk along a directed edge of the graph.  If we reach a node that is terminal (that is, it has no outgoing directed edges), we stop. Now, say our starting node is eventually safe if and only…

题目如下: 解题思路:本题大多数人采用DFS的方法,这里我用的是另一种方法.我的思路是建立一次初始值为空的safe数组,然后遍历graph,找到graph[i]中所有元素都在safe中的元素,把i加入safe.遍历完graph后继续重头遍历,直到某一次遍历后无新元素加入safe后停止.safe即为题目要求的答案.以上面例子距离,首先safe是空,第一次遍历graph后,safe=[5,6];第二次遍历后将2和4加入safe:第三次遍历后无新元素加入,safe最终结果为[5,6,2,4] 代码如下…

In a directed graph, we start at some node and every turn, walk along a directed edge of the graph.  If we reach a node that is terminal (that is, it has no outgoing directed edges), we stop. Now, say our starting node is eventually safe if and only…

In a directed graph, we start at some node and every turn, walk along a directed edge of the graph.  If we reach a node that is terminal (that is, it has no outgoing directed edges), we stop. Now, say our starting node is eventually safe if and only…

图基础 图(Graph)应用广泛,程序中可用邻接表和邻接矩阵表示图.依据不同维度,图可以分为有向图/无向图.有权图/无权图.连通图/非连通图.循环图/非循环图,有向图中的顶点具有入度/出度的概念. 面对图相关问题,第一步是将问题转为用图表示(邻接表/邻接矩阵),二是使用图相关算法求解. 相关LeetCode题: 997. Find the Town Judge  题解 1042. Flower Planting With No Adjacent  题解 图的遍历(DFS/BFS) 图的遍历/搜索…

DFS基础 深度优先搜索(Depth First Search)是一种搜索思路,相比广度优先搜索(BFS),DFS对每一个分枝路径深入到不能再深入为止,其应用于树/图的遍历.嵌套关系处理.回溯等,可以用递归.堆栈(stack)实现DFS过程. 关于广度优先搜索(BFS)详见:算法与数据结构基础 - 广度优先搜索(BFS) 关于递归(Recursion)详见:算法与数据结构基础 - 递归(Recursion) 树的遍历 DFS常用于二叉树的遍历,关于二叉树详见: 算法与数据结构基础 - 二叉查找树…