463. 岛屿的周长

;(function () {
  /**
   * 463. 岛屿的周长
   *
   */

  function islandPerimeter(grid: number[][]): number {
    // 方法一：
    let res: number = 0
    for (let i = 0; i < grid.length; i++) {
      // 计算所有岛屿格子数
      let count: number = 0
      // 计算上下重叠的格子数
      let isOverlapping: number = 0
      // 计算左右不重叠的格子数
      let lrCount: number = 0
      for (let j = 0; j < grid[i].length; j++) {
        if (grid[i][j] === 1) {
          count !== 0 && grid[i][j - 1] === 0 && lrCount++
          count++
        }
        if (i > 0) {
          grid[i][j] && grid[i - 1][j] && isOverlapping++
        }
      }
      if (count > 0) {
        res += count * 2 + 2
        // 还需要减去重叠的边。每重叠 N 个格子，就要去掉 2N 条边
        res -= isOverlapping * 2
        res += lrCount * 2
        // console.log('Count: ', count)
        // console.log('isOverlapping: ', isOverlapping)
        // console.log('lrCount: ', lrCount)
      }
    }
    return res
  }

  let grid = [
    [0, 1, 0, 0],
    [1, 1, 1, 0],
    [0, 1, 0, 0],
    [1, 1, 0, 0]
  ]
  let grid2 = [[1]]
  let grid3 = [[1, 0]]
  let grid4 = [[1], [0]]
  let grid5 = [
    [1, 1, 1],
    [1, 0, 1]
  ]
  console.log(islandPerimeter(grid))
  console.log(islandPerimeter(grid2))
  console.log(islandPerimeter(grid3))
  console.log(islandPerimeter(grid4))
  console.log(islandPerimeter(grid5))
})()