[Graph] baekjoon-21278

Author: Seogeurim

README.md

@@ -289,6 +289,7 @@
 | 06  | ⭐️  | [Baekjoon-5719 거의 최단 경로](./src/Graph/P5719)        | Dijkstra       |
 | 07  |     | [Baekjoon-9205 맥주 마시면서 걸어가기](./src/Graph/P9205)  | Floyd-Warshall |
 | 08  |     | [SWEA-1263 사람 네트워크2](./src/Graph/swea1263)         | Floyd-Warshall |
+| 09  |     | [Baekjoon-21278 호석이 두 마리 치킨](./src/Graph/P21278)  | Floyd-Warshall |
 
 ## Math
 

src/Graph/P21278/Main.java

@@ -0,0 +1,62 @@
+package Graph.P21278;
+
+import java.io.BufferedReader;
+import java.io.FileInputStream;
+import java.io.InputStreamReader;
+import java.util.StringTokenizer;
+
+public class Main {
+
+    final static int INF = 201;
+    static int N, M;
+    static int[][] D;
+
+    public static void main(String[] args) throws Exception {
+        System.setIn(new FileInputStream("src/Graph/P21278/input.txt"));
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st = new StringTokenizer(br.readLine());
+
+        N = Integer.parseInt(st.nextToken());
+        M = Integer.parseInt(st.nextToken());
+
+        D = new int[N+1][N+1];
+        for (int i = 1; i <= N; i++) {
+            for (int j = 1; j <= N; j++) {
+                if (i != j) D[i][j] = INF;
+            }
+        }
+
+        while (M-- > 0) {
+            st = new StringTokenizer(br.readLine());
+            int A = Integer.parseInt(st.nextToken());
+            int B = Integer.parseInt(st.nextToken());
+            D[A][B] = 2;
+            D[B][A] = 2;
+        }
+
+        for (int k = 1; k <= N; k++) {
+            for (int i = 1; i <= N; i++) {
+                for (int j = 1; j <= N; j++) {
+                    D[i][j] = Math.min(D[i][j], D[i][k] + D[k][j]);
+                }
+            }
+        }
+
+        int I = 0, J = 0, min = Integer.MAX_VALUE;
+        for (int i = 1; i < N; i++) {
+            for (int j = i+1; j <= N; j++) {
+                int sum = 0;
+                for (int k = 1; k <= N; k++) {
+                    sum += Math.min(D[i][k], D[j][k]);
+                }
+                if (sum < min) {
+                    I = i;
+                    J = j;
+                    min = sum;
+                }
+            }
+        }
+
+        System.out.println(I + " " + J + " " + min);
+    }
+}

src/Graph/P21278/README.md

@@ -0,0 +1,5 @@
+## [baekjoon-21278] 호석이 두 마리 치킨
+
+![image](https://user-images.githubusercontent.com/22045163/113171455-7027ea80-9282-11eb-8622-e7fe4113fdd9.png)
+
+![image](https://user-images.githubusercontent.com/22045163/113171495-7d44d980-9282-11eb-9bbc-a6597393e937.png)

src/Graph/P21278/input.txt

@@ -0,0 +1,5 @@
+5 4
+1 3
+4 2
+2 5
+3 2