[20251105] PGM / LV2 / 방문 길이 / 이인희

LiiNi-coder/202511/05 PGM 방문 길이.md

@@ -0,0 +1,61 @@
+```java
+import java.util.*;
+
+class Solution {
+    static class Coords {
+        int x1, y1, x2, y2;
+        public Coords(int x1,int y1, int x2, int y2){
+            this.x1 = x1;
+            this.y1 = y1;
+            this.x2 = x2;
+            this.y2 = y2;
+        }
+        @Override
+        public boolean equals(Object o){
+            if(!(o instanceof Coords))
+                return false;
+            Coords c = (Coords)o;
+            return (this.x1 == c.x1 && this.y1 == c.y1 && this.x2 == c.x2 && this.y2 == c.y2) || (this.x1 == c.x2 && this.y1 == c.y2 && this.x2 == c.x1 && this.y2 == c.y1);
+        }
+
+        @Override
+        public int hashCode(){
+            // 이렇게 순서를 맞춰줘야 함
+            int sx1 = Math.min(x1, x2);
+            int sx2 = Math.max(x1, x2);
+            int sy1 = Math.min(y1, y2);
+            int sy2 = Math.max(y1, y2);
+            return Objects.hash(sx1, sy1, sx2, sy2);
+            // return Objects.hash(x1, x2, y1, y2);
+        }
+    }
+
+    public int solution(String dirs) {
+        int answer = 0;
+        HashSet<Coords> set = new HashSet<>();
+        int x = 0;
+        int y = 0;
+        for(char d: dirs.toCharArray()){
+            int nx = x;
+            int ny = y;
+            if(d == 'U')
+                ny++;
+            else if(d == 'D')
+                ny--;
+            else if(d == 'R')
+                nx++;
+            else if(d == 'L')
+                nx--;
+
+            if(nx < -5 || nx > 5 || ny < -5 || ny > 5)
+                continue;
+            set.add(new Coords(x, y, nx, ny));
+            x = nx;
+            y = ny;
+        }
+        answer = set.size();
+        return answer;
+    }
+}
+
+```