BOJ - 경로 찾기

https://www.acmicpc.net/problem/11403

11403번: 경로 찾기

 

• 너비우선탐색으로 풀려다가 힌트에 플로이드워셜이 있길래 해당 알고리즘으로 공략했다.

 

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.*;


public class Main {
    public static final BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

    public static void main(String[] args) throws Exception {
        int N = Integer.parseInt(br.readLine());

        int[][] arr = new int[N][N];

        StringBuilder builder = new StringBuilder();
        StringTokenizer st;
        for (int i = 0; i < N; i++) {
            st = new StringTokenizer(br.readLine());
            for (int j = 0; j < N; j++) {
                arr[i][j] = Integer.parseInt(st.nextToken());
                if (arr[i][j] == 0)
                    arr[i][j] = 999999;
            }
        }

        for (int k = 0; k < N; k++) {
            for (int i = 0; i < N; i++) {
                for (int j = 0; j < N; j++) {
                    arr[i][j] = Math.min(arr[i][j], arr[i][k] + arr[k][j]);
                }
            }
        }

        for (int i = 0; i < N; i++) {
            for (int j = 0; j < N; j++) {
                if(arr[i][j] == 999999) {
                    builder.append("0 ");
                } else {
                    builder.append("1 ");
                }
            }
            builder.append("\n");
        }

        System.out.println(builder);
    }
}