[20250822] PGM / LV2 / 지게차와 크레인 / 이인희

Author: LiiNi-coder

LiiNi-coder/202508/22 PGM 지게차와 크레인.md

@@ -0,0 +1,113 @@
+```java
+import java.util.*;
+
+class Solution {
+    static class Point{
+        int r;
+        int c;
+        Point(int r, int c){
+            this.r = r;
+            this.c = c;
+        }
+        Point translate(int dr, int dc){
+            return new Point(r+dr, c+dc);
+        }
+    }
+    private static int[][] Drdcs = {
+        {0, 1},
+        {1, 0},
+        {0, -1},
+        {-1, 0}
+    };
+    private static int R;
+    private static int C;
+    private static int[][] Map;
+    private static HashMap<Integer, LinkedList<Point>> PointsOfId;
+    public int solution(String[] storages, String[] requests) {
+        C = storages[0].length();
+        R = storages.length;
+        int answer = R*C;
+        Map = new int[R+2][C+2];
+        PointsOfId = new HashMap<Integer, LinkedList<Point>>();
+        for(int r = 0; r < R; r++){
+            String storage = storages[r];
+            for(int c = 0; c< C; c++){
+                char cc = storage.charAt(c);
+                int id = cc - 'A' + 1;
+                var points = PointsOfId.get(id);
+                if(points == null){
+                    points = new LinkedList<Point>();
+                    PointsOfId.put(id, points);
+                }
+                points.add(new Point(r+1, c+1));
+                Map[r+1][c+1] = id;
+            }
+        }
+        
+        Integer preTarget = null;
+        for(String request: requests){
+            int target = request.charAt(0) - 'A'+1;
+            if(request.length() != 1){
+                // for(Point p: PointsOfId.get(target)){ 런타임 에러!!!!
+                //     Map[p.r][p.c] = 0;
+                //     answer--;
+                // }
+                for(Point p: PointsOfId.getOrDefault(target, new LinkedList<Point>())){
+                    Map[p.r][p.c] = 0;
+                    answer--;
+                }
+                continue;
+            }
+            var visited = new boolean[R+2][C+2];
+            
+            var startP = new Point(0, 0);
+            visit(visited, startP);
+            var q = new ArrayDeque<Point>();
+            q.offer(startP);
+            while(!q.isEmpty()){
+                Point p = q.poll();
+                for(int[] drdc: Drdcs){
+                    var nextP = p.translate(drdc[0], drdc[1]);
+                    if(BC(nextP)) continue;
+                    if(isVisit(visited, nextP)) continue;
+                    if(getIdAt(nextP) == target){
+                        Map[nextP.r][nextP.c] = 0;
+                        visit(visited, nextP);
+                    }else if(getIdAt(nextP) == 0){
+                        visit(visited, nextP);
+                        q.offer(nextP);
+                    }
+                }
+            }
+            // p(Map);
+            // System.out.println();
+        }
+        
+        int a2 = 0;
+        for(int r = 0; r<R+2; r++)
+            for(int c = 0; c<C+2; c++)
+                if(Map[r][c]!=0) a2++;
+        return a2;
+    }
+    
+    private void p(int[][] map){
+        for(int[] m: map){
+            System.out.println(Arrays.toString(m));
+        }
+    }
+    private int getIdAt(Point p){
+        return Map[p.r][p.c];
+    }
+    private void visit(boolean[][] v, Point p ){
+        v[p.r][p.c] = true;
+    }
+    private boolean isVisit(boolean[][] v, Point p ){
+        return v[p.r][p.c];
+    }
+    private boolean BC(Point p){
+        int r = p.r;
+        int c = p.c;
+        return r < 0 || r>= R+2 || c < 0 || c>=C+2;
+    }
+}
+```