미로 최단거리 문제 – 프로그래밍 콘테스트 챌린징 책 P50 문제
너비 우선 탐색을 통해 문제를 풀음.
import java.util.LinkedList; import java.util.Queue; import java.util.Scanner; class Save { public int x; public int y; public int num; public Save(int x, int y, int num { this.x = x; this.y = y; this.num = num; } } public class Miro { public static void main(String[] args) { int x, y; int num = 0; int start_x = 0; int start_y = 0; int[][] arr = new int[102][102]; Queue<Save> queue = new LinkedList<Save>(); Scanner scan = new Scanner(System.in); x = scan.nextInt(); y = scan.nextInt(); for (int i = 0; i <= x + 1; i++) { for (int j = 0; j <= y + 1; j++) { arr[i][j] = -100; } } for (int i = 1; i <= x; i++) { char[] tmp = scan.next().toCharArray(); for (int j = 0; j < y; j++) { if (tmp[j] == 'S') { start_x = i; start_y = j + 1; } else if (tmp[j] == '.') { arr[i][j + 1] = 0; } else if (tmp[j] == 'G') { arr[i][j + 1] = Integer.MAX_VALUE; } } } queue.add(new Save(start_x, start_y, num)); while (!queue.isEmpty()) { Save now = queue.poll(); num = ++now.num; if (arr[now.x][now.y] == Integer.MAX_VALUE) { break; } arr[now.x][now.y] = now.num; if (arr[now.x - 1][now.y] == 0) { queue.add(new Save(now.x - 1, now.y, now.num)); } if (arr[now.x][now.y - 1] == 0) { queue.add(new Save(now.x, now.y - 1, now.num)); } if (arr[now.x + 1][now.y] == 0) { queue.add(new Save(now.x + 1, now.y, now.num)); } if (arr[now.x][now.y + 1] == 0) { queue.add(new Save(now.x, now.y + 1, now.num)); } } System.out.println(num); } }