1765.js

/** ------------------------------------------------------------------------------
 * 
 * 1765. Map of Highest Peak
 * Topics: BFS, Matrix
 * https://leetcode.com/problems/map-of-highest-peak/description/?envType=daily-question&envId=2025-01-22
 * 
 ------------------------------------------------------------------------------ */
/**
 * @param {number[][]} isWater
 * @return {number[][]}
 */
var highestPeak = function (isWater) {
  let m = isWater.length
  let n = isWater[0].length
  const result = Array.from({ length: m }, () => Array(n).fill(-2))

  const directions = [
    [-1, 0],
    [0, 1],
    [1, 0],
    [0, -1],
  ]

  const queue = []
  let pntQueue = 0
  for (let i = 0; i < m; i++) {
    for (let j = 0; j < n; j++) {
      if (isWater[i][j] === 1) {
        queue.push(0, i, j)
      }
    }
  }

  let height, i, j
  while (pntQueue < queue.length) {
    height = queue[pntQueue++]
    i = queue[pntQueue++]
    j = queue[pntQueue++]

    if (result[i][j] < 0) {
      result[i][j] = height
      for (let [dI, dJ] of directions) {
        dI += i
        dJ += j

        if (dI >= 0 && dI < m && dJ >= 0 && dJ < n && result[dI][dJ] < -1) {
          queue.push(height + 1, dI, dJ)
          result[dI][dJ] = -1
        }
      }
    }
  }

  return result
}

console.log(
  highestPeak([
    [0, 1],
    [0, 0],
  ]),
)