Leetcode-874.js

/**
 * 874. Walking Robot Simulation
 * https://leetcode.com/problems/walking-robot-simulation/
 * @param {number[]} commands
 * @param {number[][]} obstacles
 * @return {number}
 */
/* 0 = north
 * 1 = east
 * 2 = south
 * 3 = west
 */
  
const robotSim = (commands, obstacles) => {
  let obstacle = {};
  let x = 0;
  let y = 0;
  let max = 0;
  
  let direction = 0;
  for(let i = 0; i < obstacles.length; i++) {
      obstacle[obstacles[i]] = true;
  }
  
  for(let i = 0; i < commands.length; i++) {
      
      if(commands[i] == -1) {
          direction = (direction + 1)% 4;
      } else if(commands[i] == -2) {
          direction  = ((direction - 1) + 4) % 4;
      } else {
          while(commands[i]--) {
              let previousX = x;
              let previousY = y;
              
              if(direction===0) y++;
              if(direction===1) x++;
              if(direction===2) y--;
              if(direction===3) x--;
              if(obstacle[x+','+y]) {
                  [x, y] = [previousX,previousY];
                  break;
              }
              
          }
      }
      max = Math.max(max, x**2 + y**2)
  }
  return max;
};