Minimum Knight Moves

Description

null

Solution(javascript)

/**
 * @param {number} x
 * @param {number} y
 * @return {number}
 */
const minKnightMoves = function (x, y) {
  let moves = 0
  let current = [[0, 0]]
  const visited = {
    '0-0': true,
  }
  const isValid = (x1, y1) => Math.abs(x1) + Math.abs(y1) <= 300

  while (current.length > 0) {
    const next = []
    const push = (x2, y2) => {
      const key = `${x2}-${y2}`
      if (isValid(x2, y2) && !visited[key]) {
        visited[key] = true // 加的时候就设置这个，避免加入重复的
        next.push([x2, y2])
      }
    }
    for (const [x1, y1] of Object.values(current)) {
      if (x1 === x && y1 === y) {
        return moves
      }

      push(x1 + 1, y1 + 2)
      push(x1 + 2, y1 + 1)
      push(x1 + 2, y1 - 1)
      push(x1 + 1, y1 - 2)
      push(x1 - 1, y1 - 2)
      push(x1 - 2, y1 - 1)
      push(x1 - 2, y1 + 1)
      push(x1 - 1, y1 + 2)
    }
    moves += 1
    current = next
  }
  return moves
}