Merge pull request #407 from AlgorithmWithGod/khj20006

[20250702] BOJ / G3 / 대도시 구축 / 권혁준

Author: ShinHeeEul

khj20006/202507/02 BOJ G3 대도시 구축.md

@@ -0,0 +1,120 @@
+```java
+import java.util.*;
+import java.io.*;
+
+class IOController {
+    BufferedReader br;
+    BufferedWriter bw;
+    StringTokenizer st;
+
+    public IOController() {
+        br = new BufferedReader(new InputStreamReader(System.in));
+        bw = new BufferedWriter(new OutputStreamWriter(System.out));
+        st = new StringTokenizer("");
+    }
+
+    String nextLine() throws Exception {
+        String line = br.readLine();
+        st = new StringTokenizer(line);
+        return line;
+    }
+
+    String nextToken() throws Exception {
+        while (!st.hasMoreTokens()) nextLine();
+        return st.nextToken();
+    }
+
+    int nextInt() throws Exception {
+        return Integer.parseInt(nextToken());
+    }
+
+    long nextLong() throws Exception {
+        return Long.parseLong(nextToken());
+    }
+
+    double nextDouble() throws Exception {
+        return Double.parseDouble(nextToken());
+    }
+
+    void close() throws Exception {
+        bw.flush();
+        bw.close();
+    }
+
+    void write(String content) throws Exception {
+        bw.write(content);
+    }
+
+}
+
+public class Main {
+
+    static IOController io;
+
+    //
+
+    static int N, M;
+    static int[][] infos;
+
+    public static void main(String[] args) throws Exception {
+
+        io = new IOController();
+
+        init();
+        solve();
+
+        io.close();
+
+    }
+
+    public static void init() throws Exception {
+
+        N = io.nextInt();
+        M = io.nextInt();
+        infos = new int[M][];
+        for(int i=0;i<M;i++) infos[i] = new int[]{io.nextInt(), io.nextInt()};
+
+    }
+
+    static void solve() throws Exception {
+
+        Arrays.sort(infos, (a,b) -> a[0]==b[0] ? a[1]-b[1] : a[0]-b[0]);
+        long ans = (long)N*(N+1)/2 + N-2;
+
+        if(M == 1) {
+            if(infos[0][0] == 1) {
+                if(infos[0][1] == 2) ans += 2;
+                else ans++;
+            }
+        }
+        else if(M == 2) {
+            int a = infos[0][0], b = infos[0][1];
+            int aa = infos[1][0], bb = infos[1][1];
+            if(a == 1 && aa == 1) {
+                if(b == 2) {
+                    if(bb == 3) ans += 4;
+                    else ans += 3;
+                }
+                else ans += 2;
+            }
+            else if(a == 1) {
+                if(b == 2) {
+                    if(aa == 2 && bb == 3) ans += 3;
+                    else ans += 2;
+                }
+                else {
+                    if(aa == 2 && b == bb) {
+                        if(b == 3) ans += 3;
+                        else ans += 2;
+                    }
+                    else ans++;
+                }
+            }
+        }
+
+        io.write(ans + "\n");
+
+    }
+
+}
+```