Finished livecode

src/Location.java

@@ -0,0 +1,3 @@
+public record Location(int row, int col) {
+
+}

src/Search.java

@@ -1,5 +1,25 @@
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Queue;
+import java.util.Set;
+import java.util.Map;
 public class Search {
-     /**
+    public static void main(String[] args) {
+        // Location myLoc = new Location(5, 88);
+
+        char[][] grid = {
+            {'o', 'o', 'o', 'o', 'c', 'w', 'c', 'o'},
+            {'w', 'o', 'o', 'w', 'w', 'c', 'w', 'o'},
+            {'o', 'o', 'o', 'o', 'R', 'w', 'o', 'o'},
+            {'o', 'o', 'w', 'w', 'w', 'o', 'o', 'o'},
+            {'o', 'o', 'o', 'o', 'c', 'o', 'o', 'o'}
+        };
+        System.out.println(nearestCheese(grid));
+    } 
+    /**
      * 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
      * cheeses that are tied for the same shortest distance to reach, return
@@ -29,6 +49,80 @@ public class Search {
      * @throws HungryRatException if there is no reachable cheese
      */
     public static int[] nearestCheese(char[][] maze) throws EscapedRatException, CrowdedMazeException, HungryRatException {
-        return null;
+        Location startLoc = findRat(maze);
+        Queue<Location> queue = new LinkedList<>();
+        queue.add(startLoc);
+        Set<Location> visited = new HashSet<>();
+
+        Map<Location, Location> prevs = new HashMap<>();
+        while(!queue.isEmpty()) {
+            Location current = queue.poll();
+            if (maze[current.row()][current.col()] == 'c') {
+                List<Location> path = new ArrayList<>();
+                Location pointer = current;
+                while(pointer.equals(startLoc)) {
+                    path.add(pointer);
+                    pointer = prevs.get(pointer);
+                }
+
+                path.add(startLoc);
+
+                System.out.println(path.reversed());
+                return new int[] {current.row(), current.row()};
+            };
+
+
+            for (Location neighbor : neighbors(maze, current)) {
+                if (visited.contains(neighbor)) continue;
+                visited.add(neighbor);
+                queue.add(neighbor);
+                prevs.put(neighbor, current);
+            };
+        }
+
+        throw new HungryRatException();
+    }
+
+    public static List<Location> neighbors(char[][] maze, Location currentLoc) {
+        List<Location> result = new ArrayList<>();
+
+        int[] [] moves = new int[][] {
+            { -1, 0 }, //up
+            { 1, 0 }, //down
+            { 0, -1 }, //left
+            { 0, 1 },  //right
+
+        };
+
+        for(int[] move : moves) {
+            int newR = currentLoc.row() + move[0];
+            int newC = currentLoc.col() + move[1];
+
+            if(newR >= 0 && newR < maze.length && newC >=0 && newC < maze[0].length && maze[newR][newC] != 'w'){
+                result.add(new Location(newR, newC));
+            }
+        }
+        return result;
+    }
+
+    public static Location findRat(char[][] maze) throws EscapedRatException, CrowdedMazeException {
+        Location location = null;
+        for(int row  = 0; row < maze.length; row++){
+            for(int col=0; col < maze[row].length; col++){
+                if(maze[row][col] == 'R'){
+                    if(location == null){
+                        location = new Location(row, col);
+                    } else{
+                        throw new CrowdedMazeException();
+                    }
+                }
+            }
+        }
+
+        if(location == null){
+            throw new EscapedRatException();
+        }
+
+        return location;
     }
 }