[20251224] BOJ / G4 / 플로이드 / 이인희

LiiNi-coder/202512/24 BOJ 플로이드.md

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+```java
+import java.io.*;
+import java.util.*;
+
+public class Main {
+	static final int INF = 1_000_000_000;
+
+	public static void main(String[] args) throws IOException {
+		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+		int N = Integer.parseInt(br.readLine());
+		int M = Integer.parseInt(br.readLine());
+		int[][] dist = new int[N + 1][N + 1];
+		for(int i = 1; i <= N; i++){
+			for(int j = 1; j <= N; j++){
+				if(i == j){
+					dist[i][j] = 0;
+				} else {
+					dist[i][j] = INF;
+				}
+			}
+		}
+
+		for(int i = 0; i < M; i++){
+			StringTokenizer st = new StringTokenizer(br.readLine());
+			int s = Integer.parseInt(st.nextToken());
+			int e = Integer.parseInt(st.nextToken());
+			int w = Integer.parseInt(st.nextToken());
+			dist[s][e] = Math.min(dist[s][e], w);
+		}
+		//플루이드워셜
+		for(int k = 1; k <= N; k++){
+			for(int i = 1; i <= N; i++){
+				for(int j = 1; j <= N; j++){
+					if(dist[i][j] > dist[i][k] + dist[k][j]){
+						dist[i][j] = dist[i][k] + dist[k][j];
+					}
+				}
+			}
+		}
+
+		StringBuilder sb = new StringBuilder();
+		for(int i = 1; i <= N; i++){
+			for(int j = 1; j <= N; j++){
+				if(dist[i][j] == INF){
+					sb.append(0).append(" ");
+				} else {
+					sb.append(dist[i][j]).append(" ");
+				}
+			}
+			sb.append("\n");
+		}
+		System.out.println(sb.toString());
+	}
+}
+
+```