[백준 11562] 백양로 브레이크 - 최단경로, 플로이드워셜

Author: HiiWee

hoseok/week80/Boj11562.java

@@ -0,0 +1,55 @@
+import java.io.*;
+import java.util.*;
+
+class Main {
+    static int n, m, k;
+
+    public static void main(String[] args) throws Exception {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+        StringTokenizer st = new StringTokenizer(br.readLine());
+        n = Integer.parseInt(st.nextToken());
+        m = Integer.parseInt(st.nextToken());
+
+        int[][] graph = new int[n + 1][n + 1];
+        for (int i = 0; i <= n; i++) {
+            Arrays.fill(graph[i], 1_000_000);
+            graph[i][i] = 0;
+        }
+        for (int i = 0; i < m; i++) {
+            st = new StringTokenizer(br.readLine());
+            int u = Integer.parseInt(st.nextToken());
+            int v = Integer.parseInt(st.nextToken());
+            int b = Integer.parseInt(st.nextToken());
+            if (b == 1) {
+                graph[u][v] = 0;
+                graph[v][u] = 0;
+            } else {
+                graph[u][v] = 0;
+                graph[v][u] = 1;
+            }
+        }
+
+        for (int middle = 1; middle <= n; middle++) {
+            for (int from = 1; from <= n; from++) {
+                for (int to = 1; to <= n; to++) {
+                    graph[from][to] = Math.min(graph[from][middle] + graph[middle][to], graph[from][to]);
+                }
+            }
+        }
+
+        k = Integer.parseInt(br.readLine());
+        StringBuilder answer = new StringBuilder();
+        
+        while (k-- > 0) {
+            st = new StringTokenizer(br.readLine());
+            int a = Integer.parseInt(st.nextToken());
+            int b = Integer.parseInt(st.nextToken());
+            answer.append(graph[a][b]).append("\n");
+        }
+
+        bw.write(answer.toString());
+        bw.flush();
+        bw.close();
+    }
+}