livecode

src/Search.java

@@ -1,3 +1,9 @@
+import java.util.ArrayList;
+import java.util.Currency;
+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.
@@ -29,6 +35,104 @@ public class Search {
      * @throws HungryRatException if there is no reachable cheese
      */
     public static int[] nearestCheese(char[][] maze) throws EscapedRatException, CrowdedMazeException, HungryRatException {
-        return null;
+
+       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.pop
+            int[] current = queue.poll();
+            int curR = current[0];
+            int curC = current[1];
+            //if visited: continue
+            if(visited[curR][curC]){
+                continue;
+            }
+            //mark visited
+            visited[curR][curC] =true;
+
+            //if current is cheese: return current
+            if(maze[curR][curC] == 'c'){
+                return current;
+            }
+            List<int[]> neighbors = getNeighbors(maze, current); 
+            //add all neighbors to queue
+            // for(int[] neighbor : getNeighbors(maze, current)){      
+            // } OR|
+            //add all 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];
+
+        int [][] directions ={
+            //up [-1, 0]
+            {-1, 0},
+             //down[1, 0]
+            {1, 0},
+            //left[0, -1]
+            {0, -1},
+             //right [0, 1]
+            {0, 1}
+        };
+
+        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, HungryRatException {
+        int[] location = null;
+        //serching
+        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){
+             //404 rat not found
+        throw new EscapedRatException();
+        }
+        return location;
+
     }
 }