Repository navigation
Expand file tree
/
Copy pathprob118669.java
More file actions
139 lines (117 loc) · 4.35 KB
/
Copy pathprob118669.java
File metadata and controls
139 lines (117 loc) · 4.35 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
package programmers;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.PriorityQueue;
public class prob118669 {
private static ArrayList<ArrayList<Node>> graph = new ArrayList<>();
private static int minIntensity;
private static int minSummit;
public static int[] solution(int n, int[][] paths, int[] gates, int[] summits) {
initGraph(n, paths);
HashSet<Integer> summitSet = getSummitSet(summits);
for (int gate : gates) {
gate--;
int[] distance = dijkstra(gate, n, summitSet);
for (int summit : summits) {
if (distance[summit] > minIntensity) {
continue;
}
if (distance[summit] == minIntensity) {
minSummit = Math.min(minSummit, summit);
continue;
}
minIntensity = distance[summit];
minSummit = summit;
}
}
return new int[] { minSummit + 1, minIntensity };
}
private static HashSet<Integer> getSummitSet(int[] summits) {
HashSet<Integer> summitSet = new HashSet<>();
for (int i = 0; i < summits.length; i++) {
summitSet.add(--summits[i]);
}
return summitSet;
}
private static int[] dijkstra(int start, int n, HashSet<Integer> summitSet) {
int[] distances = new int[n];
for (int i = 0; i < n; i++) {
distances[i] = Integer.MAX_VALUE;
}
distances[start] = 0;
PriorityQueue<Node> pq = new PriorityQueue<>();
pq.add(new Node(start, 0, false));
while (!pq.isEmpty()) {
Node now = pq.poll();
if (distances[now.vertex] < now.cost || minIntensity < now.cost) {
continue;
}
for (Node next : graph.get(now.vertex)) {
int intensity = Math.max(now.cost, next.cost);
if (distances[next.vertex] > intensity && !(now.isDone && summitSet.contains(next.vertex))) {
distances[next.vertex] = intensity;
pq.add(new Node(next.vertex, intensity, summitSet.contains(next.vertex) || now.isDone));
}
}
}
return distances;
}
private static void initGraph(int n, int[][] paths) {
minIntensity = Integer.MAX_VALUE;
minSummit = Integer.MAX_VALUE;
graph.clear();
for (int i = 0; i < n; i++) {
graph.add(new ArrayList<>());
}
for (int[] path : paths) {
int n1 = path[0] - 1;
int n2 = path[1] - 1;
int cost = path[2];
graph.get(n1).add(new Node(n2, cost, false));
graph.get(n2).add(new Node(n1, cost, false));
}
}
private static final class Node implements Comparable<Node> {
int vertex;
int cost;
boolean isDone;
Node(int vertex, int cost, boolean isDone) {
this.vertex = vertex;
this.cost = cost;
this.isDone = isDone;
}
@Override
public int compareTo(Node n) {
return this.cost == n.cost ? this.vertex - n.vertex : this.cost - n.cost;
}
@Override
public String toString() {
return "(" + vertex + "," + cost + ")";
}
}
public static void main(String[] args) {
int[] n = { 6, 7, 7, 5 };
int[][][] paths = {
{ { 1, 2, 3 }, { 2, 3, 5 }, { 2, 4, 2 }, { 2, 5, 4 }, { 3, 4, 4 }, { 4, 5, 3 }, { 4, 6, 1 },
{ 5, 6, 1 } },
{ { 1, 4, 4 }, { 1, 6, 1 }, { 1, 7, 3 }, { 2, 5, 2 }, { 3, 7, 4 }, { 5, 6, 6 } },
{ { 1, 2, 5 }, { 1, 4, 1 }, { 2, 3, 1 }, { 2, 6, 7 }, { 4, 5, 1 }, { 5, 6, 1 }, { 6, 7, 1 } },
{ { 1, 3, 10 }, { 1, 4, 20 }, { 2, 3, 4 }, { 2, 4, 6 }, { 3, 5, 20 }, { 4, 5, 6 } } };
int[][] gates = { { 1, 3 },
{ 1 },
{ 3, 7 },
{ 1, 2 } };
int[][] summits = { { 5 },
{ 2, 3, 4 },
{ 1, 5 },
{ 5 } };
// [5, 3]
// [3, 4]
// [5, 1]
// [5, 6]
for (int i = 0; i < n.length; i++) {
int[] ans = solution(n[i], paths[i], gates[i], summits[i]);
System.out.println(ans[0] + " " + ans[1]);
}
}
}