BOJ_6497 : 전력난

Author: spring0913

week8/BOJ_6497(전력난).java

@@ -0,0 +1,64 @@
+import java.io.*;
+import java.util.*;
+
+public class Main {
+    public static int[] parent;
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringBuilder sb = new StringBuilder();
+        while(true) {
+            StringTokenizer st = new StringTokenizer(br.readLine());
+            int N = Integer.parseInt(st.nextToken());
+            int M = Integer.parseInt(st.nextToken());
+            if(N == 0 && M == 0) {
+                System.out.print(sb);
+                return;
+            }
+            parent = new int[N + 1];
+            for (int i = 0; i < N; i++) {
+                parent[i] = i;
+            }
+            PriorityQueue<int[]> pq = new PriorityQueue<>((o1, o2) -> Integer.compare(o1[2], o2[2]));
+            long totalCost = 0;
+            for (int i = 0; i < M; i++) {
+                st = new StringTokenizer(br.readLine());
+                int A = Integer.parseInt(st.nextToken());
+                int B = Integer.parseInt(st.nextToken());
+                int C = Integer.parseInt(st.nextToken());
+                totalCost += C;
+                pq.offer(new int[]{A, B, C});
+            }
+            long minCost = 0;
+            while (!pq.isEmpty()) {
+                int[] edge = pq.poll();
+                int v1 = edge[0];
+                int v2 = edge[1];
+                int cost = edge[2];
+
+                if (union(v1, v2)) {
+                    minCost += cost;
+                }
+            }
+            sb.append(totalCost - minCost).append('\n');
+        }
+    }
+
+    public static int find(int x) {
+        if(parent[x] == x) {
+            return x;
+        }
+        parent[x] = find(parent[x]);
+        return parent[x];
+    }
+
+    public static boolean union(int x, int y) {
+        x = find(x);
+        y = find(y);
+        if(x == y) {
+            return false;
+        }
+        parent[y] = x;
+        return true;
+    }
+}