Pseudo Test | GrassHoppers

Pseudocode Challenge

Challenge: Challenge: Minimum Steps in a Maze

Problem Statement:

You are given a 2D grid representing a maze where:

0 represents an open path,
1 represents a wall, and
S represents the starting point of the maze.
E represents the exit.

The goal is to find the minimum number of steps required to reach the exit from the starting point. You can move up, down, left, or right, but cannot move through walls.

If the exit cannot be reached, return -1.

Constraints:

The grid is an n x m matrix (1 ≤ n, m ≤ 100).
There is always exactly one starting point and one exit in the maze.

Write your pseudocode below

Feedback on your code

Correct Code

function minStepsInMaze(maze):
rows = number of rows in maze
cols = number of columns in maze

# Find the coordinates of the start (S) and exit (E)
start = findCoordinates(maze, 'S')
exit = findCoordinates(maze, 'E')

# Direction vectors for moving up, down, left, right
directions = [(0, 1), (1, 0), (0, -1), (-1, 0)]

# Queue for BFS that stores (x, y, steps) where steps is the count of moves taken
queue = Queue()
queue.enqueue((start[0], start[1], 0)) # Enqueue start with 0 steps

# Visited set to track visited cells and avoid cycles
visited = set()
visited.add((start[0], start[1]))

# BFS loop
while not queue.isEmpty():
(x, y, steps) = queue.dequeue()

# If we have reached the exit, return the number of steps taken
if (x, y) == exit:
return steps

# Explore neighbors
for direction in directions:
newX = x + direction[0]
newY = y + direction[1]

# Check if new coordinates are within bounds and path is open
if isValid(newX, newY, rows, cols) and maze[newX][newY] != '1' and (newX, newY) not in visited:
# Mark new cell as visited
visited.add((newX, newY))
# Enqueue new cell with incremented step count
queue.enqueue((newX, newY, steps + 1))

# If we exhaust the queue without finding the exit, return -1
return -1

# Helper function to check bounds
function isValid(x, y, rows, cols):
return 0 <= x < rows and 0 <= y < cols

# Helper function to locate the coordinates of a target (S or E) in the grid
function findCoordinates(maze, target):
for i in range(0, len(maze)):
for j in range(0, len(maze[0])):
if maze[i][j] == target:
return (i, j)