[백준 16202] MST 게임 - MST

Author: HiiWee

hoseok/week80/Boj16202.java

@@ -0,0 +1,89 @@
+import java.io.*;
+import java.util.*;
+
+class Main {
+
+    static class Edge {
+        int a, b, cost;
+
+        public Edge(int a, int b, int cost) {
+            this.a = a;
+            this.b = b;
+            this.cost = cost;
+        }
+    }
+
+    static int n, m, k;
+    static Edge[] edges;
+    static int[] parents;
+
+    public static void main(String[] args) throws Exception {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+        StringTokenizer st = new StringTokenizer(br.readLine());
+        n = Integer.parseInt(st.nextToken());
+        m = Integer.parseInt(st.nextToken());
+        k = Integer.parseInt(st.nextToken());
+        edges = new Edge[m];
+
+        for (int i = 0; i < m; i++) {
+            st = new StringTokenizer(br.readLine());
+            int a = Integer.parseInt(st.nextToken());
+            int b = Integer.parseInt(st.nextToken());
+            edges[i] = new Edge(a, b, i + 1);
+        }
+
+        StringBuilder answer = new StringBuilder();
+        for (int edgeCost = 1; edgeCost <= k; edgeCost++) {
+            parents = new int[n + 1];
+            for (int i = 0; i <= n; i++) {
+                parents[i] = i;
+            }
+
+            int count = 0;
+            int sum = 0;
+
+            for (int i = edgeCost; i <= m && count < n - 1; i++) {
+                Edge edge = edges[i - 1];
+
+                if (union(edge.a, edge.b)) {
+                    count++;
+                    sum += edge.cost;
+                }
+            }
+
+            if (count < n - 1) {
+                answer.append("0 ");
+            } else {
+                answer.append(sum).append(" ");
+            }
+        }
+
+        bw.write(answer.toString());
+        bw.flush();
+        bw.close();
+    }
+
+    public static boolean union(int a, int b) {
+        a = find(a);
+        b = find(b);
+
+        if (a == b) {
+            return false;
+        }
+        if (a > b) {
+            parents[a] = b;
+        } else {
+            parents[b] = a;
+        }
+        return true;
+    }
+
+    public static int find(int a) {
+        if (a == parents[a]) {
+            return a;
+        }
+
+        return parents[a] = find(parents[a]);
+    }
+}