Count Ways Through a Grid With Obstacles | Dataford Interview Questions

Given a 2D matrix with obstacles, find the total number of different ways to get from the start position (x,y) to the goal position (x,y).

Implement count_paths(matrix, start, goal). The matrix contains 0 for an open cell and 1 for an obstacle; movement is restricted to right and down. Return 0 when the start or goal is blocked, the coordinates are invalid for right/down movement, or no path exists.

Constraints

1 <= len(matrix) <= 100
1 <= len(matrix[0]) <= 100
All matrix rows have the same length
matrix[row][col] is either 0 or 1
start and goal are valid coordinate pairs
Movement is restricted to right and down

Function Signature

def count_paths(matrix, start, goal):

Your question is Count Ways Through a Grid With Obstacles. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

Problem

Given a 2D matrix with obstacles, find the total number of different ways to get from the start position (x,y) to the goal position (x,y).

Constraints

1 <= len(matrix) <= 100
1 <= len(matrix[0]) <= 100
All matrix rows have the same length
matrix[row][col] is either 0 or 1
start and goal are valid coordinate pairs
Movement is restricted to right and down

Function Signature

def count_paths(matrix, start, goal):

Your question is Count Ways Through a Grid With Obstacles. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.