Completed in class code

src/Search.java

@@ -1,7 +1,13 @@
+import java.util.ArrayList;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Queue;
+
 public class Search {
-     /**
+    /**
      * Finds the location of the nearest reachable cheese from the rat's position.
-     * Returns a 2-element int array: [row, col] of the closest 'c'. If there are multiple
+     * Returns a 2-element int array: [row, col] of the closest 'c'. If there are
+     * multiple
      * cheeses that are tied for the same shortest distance to reach, return
      * any one of them.
      * 
@@ -24,11 +30,98 @@ public class Search {
      *
      * @param maze 2D char array representing the maze
      * @return int[] location of the closest cheese in row, column format
-     * @throws EscapedRatException if there is no rat in the maze
+     * @throws EscapedRatException  if there is no rat in the maze
      * @throws CrowdedMazeException if there is more than one rat in the maze
-     * @throws HungryRatException if there is no reachable cheese
+     * @throws HungryRatException   if there is no reachable cheese
      */
-    public static int[] nearestCheese(char[][] maze) throws EscapedRatException, CrowdedMazeException, HungryRatException {
-        return null;
+    public static int[] nearestCheese(char[][] maze)
+            throws EscapedRatException, CrowdedMazeException, HungryRatException {
+        boolean[][] visited = new boolean[maze.length][maze[0].length];
+        int[] start = ratLocation(maze);
+
+        // queue = []
+        Queue<int[]> queue = new LinkedList<>();
+        // queue.add(start)
+        queue.add(start);
+
+        // while queue not empty
+        while (!queue.isEmpty()) {
+            // current = queue.poll
+            int[] current = queue.poll();
+            int curR = current[0];
+            int curC = current[1];
+            // if visited: continue
+            if (!visited[curR][curC]) {
+                // mark visited
+                visited[curR][curC] = true;
+                // if current is cheese: return current
+                if (maze[curR][curC] == 'c') {
+                    return current;
+                }
+                // add neighbors to queue
+                queue.addAll(getNeighbors(maze, current));
+            }
+        }
+
+        // throw hungee
+        throw new HungryRatException();
+    }
+
+    public static List<int[]> getNeighbors(char[][] maze, int[] current) {
+        int curR = current[0];
+        int curC = current[1];
+
+        // UP [-1, 0]
+        // DOWN [+1, 0]
+        // LEFT [0, -1]
+        // RIGHT [0, +1]
+        int[][] directions = {
+                { -1, 0 }, // UP
+                { 1, 0 }, // DOWN
+                { 0, -1 }, // LEFT
+                { 0, 1 } // RIGHT
+        };
+
+        List<int[]> possibleMoves = new ArrayList<>();
+
+        for (int[] direction : directions) {
+            int changeR = direction[0];
+            int changeC = direction[1];
+
+            int newR = curR + changeR;
+            int newC = curC + changeC;
+
+            if (newR >= 0 && newR < maze.length &&
+                    newC >= 0 && newC < maze[newR].length &&
+                    maze[newR][newC] != 'w') {
+                // valid move!
+                int[] validMove = { newR, newC };
+                possibleMoves.add(validMove);
+            }
+        }
+
+        return possibleMoves;
+    }
+
+    public static int[] ratLocation(char[][] maze) throws EscapedRatException, CrowdedMazeException {
+        int[] location = null;
+
+        // Searching
+
+        for (int r = 0; r < maze.length; r++) {
+            for (int c = 0; c < maze[r].length; c++) {
+                if (maze[r][c] == 'R') {
+                    if (location != null) {
+                        throw new CrowdedMazeException();
+                    }
+                    location = new int[] { r, c };
+                }
+            }
+        }
+
+        if (location == null) {
+            throw new EscapedRatException();
+        }
+        return location;
     }
 }