[20251210] BOJ / G4 / 친구비 / 이준희

JHLEE325/202512/10 BOJ G4 친구비.md

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+```java
+import java.io.*;
+import java.util.*;
+
+public class Main {
+
+    static int N, M, K;
+    static int[] cost;
+    static List<Integer>[] graph;
+    static boolean[] visited;
+
+    public static void main(String[] args) throws Exception {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st = new StringTokenizer(br.readLine());
+
+        N = Integer.parseInt(st.nextToken());
+        M = Integer.parseInt(st.nextToken());
+        K = Integer.parseInt(st.nextToken());
+
+        cost = new int[N + 1];
+        visited = new boolean[N + 1];
+        graph = new ArrayList[N + 1];
+
+        for (int i = 1; i <= N; i++) graph[i] = new ArrayList<>();
+
+        st = new StringTokenizer(br.readLine());
+        for (int i = 1; i <= N; i++) {
+            cost[i] = Integer.parseInt(st.nextToken());
+        }
+
+        for (int i = 0; i < M; i++) {
+            st = new StringTokenizer(br.readLine());
+            int a = Integer.parseInt(st.nextToken());
+            int b = Integer.parseInt(st.nextToken());
+            graph[a].add(b);
+            graph[b].add(a);
+        }
+
+        int totalCost = 0;
+
+        for (int i = 1; i <= N; i++) {
+            if (!visited[i]) {
+                int minCost = bfs(i);
+                totalCost += minCost;
+
+                if (totalCost > K) {
+                    System.out.println("Oh no");
+                    return;
+                }
+            }
+        }
+
+        System.out.println(totalCost);
+    }
+
+    static int bfs(int start) {
+        Queue<Integer> q = new ArrayDeque<>();
+        q.add(start);
+        visited[start] = true;
+
+        int minCost = cost[start];
+
+        while (!q.isEmpty()) {
+            int cur = q.poll();
+            minCost = Math.min(minCost, cost[cur]);
+
+            for (int next : graph[cur]) {
+                if (!visited[next]) {
+                    visited[next] = true;
+                    q.offer(next);
+                }
+            }
+        }
+        return minCost;
+    }
+}
+
+```