|
| 1 | +--- |
| 2 | +id: Maximum-Score-of-a-Node-Sequence |
| 3 | +title: Maximum-Score-of-a-Node-Sequence |
| 4 | +sidebar_label: 2242-Maximum-Score-of-a-Node-Sequence |
| 5 | +tags: |
| 6 | + - Arrays |
| 7 | + - graph |
| 8 | + - sorting |
| 9 | + - Enumeration |
| 10 | +description: "This document provides solutions to this problem implemented in Java, and Python." |
| 11 | +--- |
| 12 | + |
| 13 | +## Problem |
| 14 | + |
| 15 | +There is an undirected graph with n nodes, numbered from 0 to n - 1. |
| 16 | + |
| 17 | +You are given a 0-indexed integer array scores of length n where scores[i] denotes the score of node i. You are also given a 2D integer array edges where edges[i] = [ai, bi] denotes that there exists an undirected edge connecting nodes ai and bi. |
| 18 | + |
| 19 | +A node sequence is valid if it meets the following conditions: |
| 20 | + |
| 21 | +There is an edge connecting every pair of adjacent nodes in the sequence. |
| 22 | +No node appears more than once in the sequence. |
| 23 | +The score of a node sequence is defined as the sum of the scores of the nodes in the sequence. |
| 24 | + |
| 25 | +Return the maximum score of a valid node sequence with a length of 4. If no such sequence exists, return -1. |
| 26 | + |
| 27 | +### Examples |
| 28 | + |
| 29 | +**Example 1:** |
| 30 | + |
| 31 | +Input: scores = [5,2,9,8,4], edges = [[0,1],[1,2],[2,3],[0,2],[1,3],[2,4]] |
| 32 | +Output: 24 |
| 33 | +Explanation: The figure above shows the graph and the chosen node sequence [0,1,2,3]. |
| 34 | +The score of the node sequence is 5 + 2 + 9 + 8 = 24. |
| 35 | +It can be shown that no other node sequence has a score of more than 24. |
| 36 | +Note that the sequences [3,1,2,0] and [1,0,2,3] are also valid and have a score of 24. |
| 37 | +The sequence [0,3,2,4] is not valid since no edge connects nodes 0 and 3. |
| 38 | +### Constraints |
| 39 | + |
| 40 | +- `banknotesCount.length == 5` |
| 41 | +- `0 <= banknotesCount[i] <= 109` |
| 42 | +- `1 <= amount <= 109` |
| 43 | + |
| 44 | +### Solution |
| 45 | + |
| 46 | +#### Code in Different Languages |
| 47 | + |
| 48 | +### Java Solution |
| 49 | + |
| 50 | +```java |
| 51 | + public int maximumScore(int[] A, int[][] edges) { |
| 52 | + int n = A.length; |
| 53 | + PriorityQueue<Integer>[] q = new PriorityQueue[n]; |
| 54 | + for (int i = 0; i < n; i++) |
| 55 | + q[i] = new PriorityQueue<>((a, b) -> A[a] - A[b]); |
| 56 | + for (int[] e : edges) { |
| 57 | + q[e[0]].offer(e[1]); |
| 58 | + q[e[1]].offer(e[0]); |
| 59 | + if (q[e[0]].size() > 3) q[e[0]].poll(); |
| 60 | + if (q[e[1]].size() > 3) q[e[1]].poll(); |
| 61 | + } |
| 62 | + int res = -1; |
| 63 | + for (int[] edge : edges) |
| 64 | + for (int i : q[edge[0]]) |
| 65 | + for (int j : q[edge[1]]) |
| 66 | + if (i != j && i != edge[1] && j != edge[0]) |
| 67 | + res = Math.max(res, A[i] + A[j] + A[edge[0]] + A[edge[1]]); |
| 68 | + return res; |
| 69 | + } |
| 70 | + |
| 71 | + |
| 72 | +``` |
| 73 | + |
| 74 | +### Python Solution |
| 75 | + |
| 76 | +```python |
| 77 | + def maximumScore(self, A, edges): |
| 78 | + n = len(A) |
| 79 | + G = [[] for i in range(n)] |
| 80 | + for i,j in edges: |
| 81 | + G[i].append([A[j], j]) |
| 82 | + G[j].append([A[i], i]) |
| 83 | + for i in range(n): |
| 84 | + G[i] = nlargest(3, G[i]) |
| 85 | + |
| 86 | + res = -1 |
| 87 | + for i,j in edges: |
| 88 | + for vii, ii in G[i]: |
| 89 | + for vjj, jj in G[j]: |
| 90 | + if ii != jj and ii != j and j != ii: |
| 91 | + res = max(res, vii + vjj + A[i] + A[j]) |
| 92 | + return res |
| 93 | + |
| 94 | +``` |
| 95 | + |
| 96 | +### Complexity Analysis |
| 97 | + |
| 98 | +### Time Complexity: $O(1)$ |
| 99 | + |
| 100 | +> **Reason**:Both deposit and withdraw operations are $O(1)$, assuming a fixed number of denominations. |
| 101 | +
|
| 102 | +### Space Complexity: $O(1)$ |
| 103 | + |
| 104 | +> **Reason**: for the fixed-size array or deque used to store banknote counts. |
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