200.岛屿数量.js

/*
 * @lc app=leetcode.cn id=200 lang=javascript
 *
 * [200] 岛屿数量
 */

// @lc code=start
/**
 * @param {character[][]} grid
 * @return {number}
 */
var numIslands = function(grid) {
  if (grid.length === 0 || grid[0].length === 0) {
		return 0
	}

	let count = 0
  for (let i = 0, len = grid.length; i < len; i ++) {
    for(let j = 0, len = grid[0].length; j < len; j ++) {
      if(grid[i][j] != 0) {
        count ++
        findIslandSlibings(i, j)	
      }
    }
  }

  
  function findIslandSlibings (i, j) {
    grid[i][j] = 0 // 先拿掉当前的岛屿
    if(grid[i][j + 1] == 1) {
      findIslandSlibings(i, j + 1)
    }
    if(grid[i][j - 1] == 1) {
      findIslandSlibings(i, j - 1)
    }
    if(grid[i - 1] &&　grid[i - 1][j] == 1) {
      findIslandSlibings(i - 1, j)
    }
    if(grid[i + 1] &&　grid[i + 1][j] == 1) {
      findIslandSlibings(i + 1, j)
    }
  }
  return count

};
// @lc code=end