-
Notifications
You must be signed in to change notification settings - Fork 0
/
Prim.java
65 lines (54 loc) · 1.8 KB
/
Prim.java
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
package prim;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;
public class Main {
private static int V, E;
private static boolean[] visit;
private static int[][] w;
private static int[] d;
private static int minCost = 0;
public static void main(String[] argv) throws IOException {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
StringTokenizer st = new StringTokenizer(br.readLine());
V = Integer.parseInt(st.nextToken());
E = Integer.parseInt(st.nextToken());
visit = new boolean[V+1];
w = new int[V+1][V+1];
d = new int[V+1];
for(int i=0; i<=V; ++i){
d[i] = Integer.MAX_VALUE;
for(int j=0; j<=V; ++j) w[i][j] = Integer.MAX_VALUE;
}
for(int e=0; e<E; ++e){
st = new StringTokenizer(br.readLine());
int from = Integer.parseInt(st.nextToken());
int to = Integer.parseInt(st.nextToken());
int weight = Integer.parseInt(st.nextToken());
w[from][to] = w[to][from] = weight;
}
d[1] = 0;
int numOfMST = 0;
while(numOfMST < V){
int min = Integer.MAX_VALUE;
int u = -1;
for(int i=0; i<= V; ++i){
if(!visit[i] && d[i] < min){
min = d[i];
u = i;
}
}
for(int i=1; i<=V; ++i){
if(!visit[i] && w[u][i] != Integer.MAX_VALUE){
if(w[u][i] < d[i]) d[i] = w[u][i];
}
}
numOfMST++;
minCost += min;
visit[u] = true;
}
System.out.println(minCost);
br.close();
}
}