[20260324] BOJ / P2 / Maximum Strategic Savings / 권혁준

khj20006/202603/24 BOJ P2 Maximum Strategic Savings.md

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+```java
+import java.io.*;
+import java.util.*;
+
+public class BOJ16025 {
+
+    static class DisjointSet {
+        int[] root;
+        DisjointSet(int size) {
+            root = new int[size+1];
+            for(int i=1;i<=size;i++) {
+                root[i] = i;
+            }
+        }
+
+        int find(int x) {
+            return x == root[x] ? x : (root[x] = find(root[x]));
+        }
+
+        boolean union(int a, int b) {
+            int x = find(a), y = find(b);
+            if(x == y) {
+                return false;
+            }
+            root[x] = y;
+            return true;
+        }
+    }
+    static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+    static BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+    static StringTokenizer st;
+
+    static int N, M, P, Q;
+    static int[][] edges;
+    static DisjointSet dsx, dsy;
+
+    public static void main(String[] args) throws Exception {
+        st = new StringTokenizer(br.readLine());
+        N = Integer.parseInt(st.nextToken());
+        M = Integer.parseInt(st.nextToken());
+        P = Integer.parseInt(st.nextToken());
+        Q = Integer.parseInt(st.nextToken());
+
+        edges = new int[P+Q][];
+        long sum = 0;
+        for(int i=0;i<P+Q;i++) {
+            st = new StringTokenizer(br.readLine());
+            int a = Integer.parseInt(st.nextToken());
+            int b = Integer.parseInt(st.nextToken());
+            int c = Integer.parseInt(st.nextToken());
+
+            int type = 0;
+            if(i >= P) {
+                type = 1;
+                sum += (long)c * M;
+            }
+            else {
+                sum += (long)c * N;
+            }
+            edges[i] = new int[]{a, b, c, type};
+        }
+
+        dsx = new DisjointSet(N);
+        dsy = new DisjointSet(M);
+        Arrays.sort(edges, (a,b) -> a[2]-b[2]);
+        long X = N, Y = M;
+        for(int[] edge : edges) {
+            int a = edge[0], b = edge[1], type = edge[3];
+            long c = edge[2];
+
+            if(type == 0) {
+                if(dsy.union(a, b)) {
+                    sum -= c * X;
+                    Y--;
+                }
+            }
+            else {
+                if(dsx.union(a, b)) {
+                    sum -= c * Y;
+                    X--;
+                }
+            }
+        }
+
+        bw.write(sum + "\n");
+        bw.close();
+    }
+}
+```