gistfile1.txt

function numberOfPaths (matrix) {
  // Write your code here
  if (matrix.length < 1) return 0

  // if matrix[matrix.length-1] === 0 and matrix[matrix.length -1] == 0 then return 0
  // set up 2d cache to cumulate the possible moves
  const cache = Array.from(Array(matrix.length + 1), () => new Array(matrix[0].length + 1).fill(null))
  // set up initial values

  cache[1][1] = 1

  // tabulate the total number of moves it will take to get to the y * x square
  // logic is that if we land on tile where a top or left neighbor is 0 then that path is dead
  for (let i = 1; i < cache.length; i++) {
    for (let j = 1; j < cache[i].length; j++) {
      if (cache[i][j] === null) {
        const matrixSquare = matrix[i - 1][j - 1]
        const top = matrixSquare === 1 ? cache[i - 1][j] : 0
        const left = matrixSquare === 1 ? cache[i][j - 1] : 0
        let tile = 0
        if (top === 1) tile++
        if (left === 1) tile++
        cache[i][j] = tile
      }
    }
  }

  console.log(JSON.stringify(cache, null, 1))
  return cache[matrix.length][matrix[0].length]
}

const input = [[1, 1, 0], [0, 1, 1], [1, 1, 1]]
const paths = numberOfPaths(input)
console.log(`paths: ${paths}`)