이지영 : [BOJ] 18404 현명한 나이트_240925

BOJ/15001-20000번/JY_18404.java

@@ -0,0 +1,92 @@
+package day0925;
+
+import java.util.*;
+import java.io.*;
+
+public class JY_18404 {
+
+	static int N, M;
+	static int[][] g;
+	static int[] crr;
+	static int[] dx = {-2, -2, -1, -1, 1, 1, 2, 2};
+	static int[] dy = {-1, 1, -2, 2, -2, 2, -1, 1};
+	static class Pos {
+		int x, y, cnt;
+		public Pos(int x, int y, int cnt) {
+			this.x = x;
+			this.y = y;
+			this.cnt = cnt;
+		}
+	}
+
+	public static void main(String[] args) throws IOException{
+		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+		StringTokenizer st = new StringTokenizer(br.readLine());
+
+		N = Integer.parseInt(st.nextToken());
+		M = Integer.parseInt(st.nextToken());
+
+		g = new int[N+1][N+1];
+		crr = new int[M+1];
+
+		st = new StringTokenizer(br.readLine());
+		int sx = Integer.parseInt(st.nextToken());
+		int sy = Integer.parseInt(st.nextToken());
+
+		for(int i=1; i<M+1; i++) {
+			st = new StringTokenizer(br.readLine());
+			int x = Integer.parseInt(st.nextToken());
+			int y = Integer.parseInt(st.nextToken());
+			g[x][y] = i;
+			crr[i] = Integer.MAX_VALUE;
+		}
+
+//		System.out.println("sx:"+sx+",sy:"+sy);
+//		for(int i=0; i<N+1; i++) {
+//			System.out.println(Arrays.toString(g[i]));
+//		}
+//		System.out.println(Arrays.toString(crr));
+
+		// bfs 탐색으로 최소 움직임 찾기
+		bfs(sx, sy);
+
+		for(int i=1; i<M+1; i++) {
+			System.out.print(crr[i]+" ");
+		}
+		System.out.println();
+	}
+	public static boolean inRange(int x, int y) {
+		return x>0 && x<=N && y>0 && y<=N;
+	}
+	public static void bfs(int x, int y) {
+		ArrayDeque<Pos> q = new ArrayDeque<>();
+		boolean[][] visited = new boolean[N+1][N+1];
+		q.add(new Pos(x, y, 0));
+		visited[x][y] = true;
+
+		int isDone = 0;
+		while(!q.isEmpty()) {
+			Pos now = q.poll();
+			// 상대편 말을 잡았다면 최소 움직임 기록
+			if(g[now.x][now.y] != 0) {
+				int num = g[now.x][now.y];
+				crr[num] = now.cnt;
+				isDone++;
+			}
+			// 모든 상대편 말을 잡았다면 break
+			if(isDone == M) break;
+
+			for(int i=0; i<8; i++) {
+				int nx = now.x + dx[i];
+				int ny = now.y + dy[i];
+				if(inRange(nx, ny) && !visited[nx][ny]) {
+					visited[nx][ny] = true;
+					q.add(new Pos(nx, ny, now.cnt+1));
+				}
+			}
+		}
+
+	}
+
+
+}