3600. Maximize Spanning Tree Stability with Upgrades
Hard
50 Points
Binary Search
Greedy
Union Find
Graph
Minimum Spanning Tree
You are given an integer n, representing n nodes numbered from 0 to n - 1 and a list of edges, where edges[i] = [ui, vi, si, musti]:
You are also given an integer k, the maximum number of upgrades you can perform. Each upgrade doubles the strength of an edge, and each eligible edge (with musti == 0) can be upgraded at most once.
The stability of a spanning tree is defined as the minimum strength score among all edges included in it.
Return the maximum possible stability of any valid spanning tree. If it is impossible to connect all nodes, return -1.
Note: A spanning tree of a graph with n nodes is a subset of the edges that connects all nodes together (i.e. the graph is connected) without forming any cycles, and uses exactly n - 1 edges.
Examples
Example 1
Input: n = 3, edges = [[0,1,2,1],[1,2,3,0]], k = 1
Output: 2
Explanation:
Example 2
Input: n = 3, edges = [[0,1,4,0],[1,2,3,0],[0,2,1,0]], k = 2
Output: 6
Explanation:
Example 3
Input: n = 3, edges = [[0,1,1,1],[1,2,1,1],[2,0,1,1]], k = 0
Output: -1
Explanation:
Constraints
2 <= n <= 105
1 <= edges.length <= 105
edges[i] = [ui, vi, si, musti]
0 <= ui, vi < n
ui != vi
1 <= si <= 105
musti is either 0 or 1.
0 <= k <= n
There are no duplicate edges.
3600. Maximize Spanning Tree Stability with Upgrades
Hard
50 Points
Binary Search
Greedy
Union Find
Graph
Minimum Spanning Tree
You are given an integer n, representing n nodes numbered from 0 to n - 1 and a list of edges, where edges[i] = [ui, vi, si, musti]:
You are also given an integer k, the maximum number of upgrades you can perform. Each upgrade doubles the strength of an edge, and each eligible edge (with musti == 0) can be upgraded at most once.
The stability of a spanning tree is defined as the minimum strength score among all edges included in it.
Return the maximum possible stability of any valid spanning tree. If it is impossible to connect all nodes, return -1.
Note: A spanning tree of a graph with n nodes is a subset of the edges that connects all nodes together (i.e. the graph is connected) without forming any cycles, and uses exactly n - 1 edges.
Examples
Example 1
Input: n = 3, edges = [[0,1,2,1],[1,2,3,0]], k = 1
Output: 2
Explanation:
Example 2
Input: n = 3, edges = [[0,1,4,0],[1,2,3,0],[0,2,1,0]], k = 2
Output: 6
Explanation:
Example 3
Input: n = 3, edges = [[0,1,1,1],[1,2,1,1],[2,0,1,1]], k = 0
Output: -1
Explanation:
Constraints
2 <= n <= 105
1 <= edges.length <= 105
edges[i] = [ui, vi, si, musti]
0 <= ui, vi < n
ui != vi
1 <= si <= 105
musti is either 0 or 1.
0 <= k <= n
There are no duplicate edges.
Maximize Spanning Tree Stability with Upgrades - Practice Coding | SlaveCode