add 4084

Author: fishercoder1534

paginated_contents/algorithms/5th_thousand/README.md

@@ -1,5 +1,6 @@
 | #    | Title                                                                                                                                                                                 | Solutions                                                                                                                        | Video                                | Difficulty | Tag                                                                  
 |------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------|--------------------------------------|------------|----------------------------------------------------------------------
+| 4084 | [Last Visited Cell in a Directional Grid](https://leetcode.com/problems/last-visited-cell-in-a-directional-grid/)                                                                                                       | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fifththousand/_4084.java) |                                      | Medium     |
 | 4083 | [Minimum Deletions to Make Array Sharp](https://leetcode.com/problems/minimum-deletions-to-make-array-sharp/)                                                                                                       | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fifththousand/_4083.java) |                                      | Easy       |
 | 4080 | [Design Bus Seat Booking System](https://leetcode.com/problems/design-bus-seat-booking-system/)                                                                                                       | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fifththousand/_4080.java) |                                      | Medium     |
 | 4079 | [Prime Subset Selection I](https://leetcode.com/problems/prime-subset-selection-i/)                                                                                                       | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fifththousand/_4079.java) |                                      | Medium     |

src/main/java/com/fishercoder/solutions/fifththousand/_4084.java

@@ -0,0 +1,36 @@
+package com.fishercoder.solutions.fifththousand;
+
+import java.util.HashSet;
+import java.util.Set;
+
+public class _4084 {
+    public static class Solution1 {
+        public int[] lastVisitedCell(char[][] grid) {
+            Set<Integer> visited = new HashSet<>();
+            int n = grid.length > 0 ? grid[0].length : 0;
+            int row = 0;
+            int col = 0;
+            int lastRow = 0;
+            int lastCol = 0;
+            while (!visited.contains(row * n + col)) {
+                char nextMove = grid[row][col];
+                visited.add(row * n + col);
+                lastRow = row;
+                lastCol = col;
+                if (nextMove == 'R') {
+                    col++;
+                } else if (nextMove == 'L') {
+                    col--;
+                } else if (nextMove == 'U') {
+                    row--;
+                } else {
+                    row++;
+                }
+                if (row < 0 || col < 0 || row >= grid.length || col >= grid[0].length) {
+                    break;
+                }
+            }
+            return new int[]{lastRow, lastCol};
+        }
+    }
+}