[20250804] BOJ / G3 / 전국시대 / 이종환

Author: 0224LJH

0224LJH/202508/4 BOJ 전국시대.md

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+```java
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.*;
+
+
+public class Main {
+
+    static final int WAR = 2;
+    static final int UNION = 1;
+
+    static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+    static StringBuilder sb = new StringBuilder();
+    static int[] countryPower,parent;
+    static boolean[] isAlive;
+    static int countryCnt, recordCnt,ans;
+    static List<Integer> ansList = new ArrayList<>();
+
+    public static void main(String[] args) throws IOException {
+        init();
+        process();
+        print();
+    }
+
+    private static void init() throws IOException {
+        StringTokenizer st = new StringTokenizer(br.readLine());
+        countryCnt = Integer.parseInt(st.nextToken());
+        recordCnt = Integer.parseInt(st.nextToken());
+        countryPower = new int[countryCnt];
+        parent = new int[countryCnt];
+        isAlive = new boolean[countryCnt];
+        Arrays.fill(isAlive, true);
+
+        for (int i = 0; i < countryCnt; i++) {
+            countryPower[i] = Integer.parseInt(br.readLine());
+            parent[i] = i;
+        }
+    }
+
+    private static void process() throws IOException {
+        for (int i = 0; i < recordCnt; i++) {
+            StringTokenizer st = new StringTokenizer(br.readLine());
+            int order = Integer.parseInt(st.nextToken());
+            int a = Integer.parseInt(st.nextToken())-1;
+            int b = Integer.parseInt(st.nextToken())-1;
+
+            if (order == UNION) {
+                union(a, b);
+            } else{
+                war(a,b);
+            }
+        }
+
+        for (int i = 0; i < countryCnt; i++) {
+            if (!isAlive[i]) continue;
+            int iRoot = find(i);
+            if (iRoot != i) continue;
+            if (isAlive[iRoot]) {
+                ans++;
+                ansList.add(countryPower[iRoot]);
+            }
+        }
+
+
+
+    }
+
+    private static void war(int a, int b) {
+        int aRoot = find(a);
+        int bRoot = find(b);
+
+        if (aRoot == bRoot) return;
+
+        int aPower = countryPower[aRoot];
+        int bPower = countryPower[bRoot];
+        if (aPower > bPower) {
+            countryPower[aRoot] -= bPower;
+            countryPower[bRoot] = 0;
+            parent[bRoot] = aRoot;
+            isAlive[bRoot] = false;
+        } else if (aPower < bPower) {
+            countryPower[bRoot] -= aPower;
+            countryPower[aRoot] = 0;
+            parent[aRoot] = bRoot;
+            isAlive[aRoot] = false;
+        } else{
+            countryPower[aRoot]  = 0;
+            countryPower[bRoot] = 0;
+            isAlive[aRoot] = false;
+            isAlive[bRoot] = false;
+        }
+
+
+    }
+
+    private static void union(int a, int b) {
+        int aRoot = find(a);
+        int bRoot = find(b);
+
+        if (aRoot == bRoot) return;
+
+        int aPower = countryPower[aRoot];
+        int bPower = countryPower[bRoot];
+
+        if (aPower >= bPower) {
+            countryPower[aRoot] += bPower;
+            countryPower[bRoot] = 0;
+            parent[bRoot] = aRoot;
+            isAlive[bRoot] = false;
+        } else  {
+            countryPower[bRoot] += aPower;
+            countryPower[aRoot] = 0;
+            parent[aRoot] = bRoot;
+            isAlive[aRoot] = false;
+        }
+
+    }
+
+    private static int find(int x){
+        if ( parent[x] == x ) return x;
+        return parent[x] = find(parent[x]);
+    }
+
+    private static void print() {
+        Collections.sort(ansList);
+        System.out.println(ansList.size());
+        if (!ansList.isEmpty()) {
+            for (int i = 0; i < ansList.size(); i++) {
+                System.out.print(ansList.get(i));
+                if (i < ansList.size() - 1) System.out.print(" ");
+            }
+            System.out.println();
+        }
+    }
+}
+```