problem:https://leetcode.com/contest/biweekly-contest-5/problems/connecting-cities-with-minimum-cost/ 双周赛题目。此题就是没有什么变化的最小生成树,以下给出两种经典解法: (1).并查集 首先假设所有的顶点都是一棵单独的树,之后依次选择权重最小的边,使得它连接两棵不同的树,并将两棵树合并为一棵树。...
题目地址:https://leetcode-cn.com/problems/connecting-cities-with-minimum-cost/题目描述There are N cities numbered from 1 to N.You are given connections, where each connections[i] = [city1, city2, cost] represents the cost to connect city1 and city2 together. (A connection is ...
LeetCode 1135. Connecting Cities With Minimum Cost 一道常规求minimum spanning tree的题,返回值为最小cost,出现在热带雨林厂的OA中。 难度:medium 算法:Kruskal,并查集 思路: 求MST用Kruskal或者Prim,理论上Prim在非常dense的graph中更快一点,否则Kruskal更快也更简单。 这里采用Kruskal,先对边排序,每次连最小边,...
Output: -1 Explanation: There is no way to connect all cities even if all edges are used. 其实union-find也没有那么难。一个union函数,一个find函数,哦了。 https://leetcode.com/problems/connecting-cities-with-minimum-cost/discuss/344867/Java-Kruskal's-Minimum-Spanning-Tree-Algorithm-with-Union-...
Try to connect cities with minimum cost, then find small cost edge first, if two cities connected by the edge do no have same ancestor, then union them. When number of unions equal to 1, all cities are connected. Time Complexity: O(mlogm + mlogN). sort takes O(mlogm). find takes...
Explanation: There is no way to connect all cities even if all edges are used. 其实union-find也没有那么难。一个union函数,一个find函数,哦了。 https://leetcode.com/problems/connecting-cities-with-minimum-cost/discuss/344867/Java-Kruskal's-Minimum-Spanning-Tree-Algorithm-with-Union-Find ...
Return the minimum cost so that for every pair of cities, there exists a path of connections (possibly of length 1) that connects those two cities together. The cost is the sum of the connection costs used. If the task is impossible, return -1. ...