[20250910] BOJ / G3 / 택배 / 이준희

Author: JHLEE325

JHLEE325/202509/10 BOJ G3 택배.md

@@ -0,0 +1,62 @@
+```java
+import java.io.*;
+import java.util.*;
+
+public class Main {
+    static final int INF = 987654321;
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st = new StringTokenizer(br.readLine());
+
+        int n = Integer.parseInt(st.nextToken());
+        int m = Integer.parseInt(st.nextToken());
+
+        int[][] dist = new int[n][n];
+        int[][] next = new int[n][n];
+
+        for (int i = 0; i < n; i++) {
+            Arrays.fill(dist[i], INF);
+            dist[i][i] = 0;
+            Arrays.fill(next[i], -1);
+        }
+
+        for (int i = 0; i < m; i++) {
+            st = new StringTokenizer(br.readLine());
+            int a = Integer.parseInt(st.nextToken()) - 1;
+            int b = Integer.parseInt(st.nextToken()) - 1;
+            int c = Integer.parseInt(st.nextToken());
+
+            if (c < dist[a][b]) {
+                dist[a][b] = c;
+                dist[b][a] = c;
+                next[a][b] = b;
+                next[b][a] = a;
+            }
+        }
+        
+        for (int k = 0; k < n; k++) {
+            for (int i = 0; i < n; i++) {
+                for (int j = 0; j < n; j++) {
+                    if (dist[i][j] > dist[i][k] + dist[k][j]) {
+                        dist[i][j] = dist[i][k] + dist[k][j];
+                        next[i][j] = next[i][k];
+                    }
+                }
+            }
+        }
+
+        StringBuilder sb = new StringBuilder();
+        for (int i = 0; i < n; i++) {
+            for (int j = 0; j < n; j++) {
+                if (i == j) sb.append("- ");
+                else sb.append(next[i][j] + 1).append(" ");
+            }
+            sb.append("\n");
+        }
+
+        System.out.print(sb);
+    }
+}
+
+```