JSFiddle - React, Tailwind, and code Playground

by David Kyle

JavaScript

const height = 4;
const width = 4;
const findUniquePath = (width = 1, height = 1) => {
   const board = Array(height).fill(null).map(() => {
      return Array(width).fill(0);
   });
   for (let rowIndex = 0; rowIndex < height; rowIndex += 1) {
      for (let columnIndex = 0; columnIndex < width; columnIndex += 1) {
         if (rowIndex === 0 || columnIndex === 0) {
            board[rowIndex][columnIndex] = 1;
         }
      }
   }
   for (let rowIndex = 1; rowIndex < height; rowIndex += 1) {
      for (let columnIndex = 1; columnIndex < width; columnIndex += 1) {
         const uniquesFromTop = board[rowIndex - 1][columnIndex];
         const uniquesFromLeft = board[rowIndex][columnIndex - 1];
         board[rowIndex][columnIndex] = uniquesFromTop + uniquesFromLeft;
      }
   }
   return board[height - 1][width - 1];
};
alert(findUniquePath(width, height));