Leetcode 605 - Can Place Flowers

Note:

  • How to be greedy? As long the current plot can be planted, let’s do it.
  • Special cases for the start and end.
  • The reason behind this:
    • For example: [0,0,0] can be planted as [1,0,1] or [0,1,0].
    • But because we iterate from left to right, as long as we planted at every possible plot, the result will be the maximum. It won’t happen like [0,1,0].

Question:

You have a long flowerbed in which some of the plots are planted, and some are not. However, flowers cannot be planted in adjacent plots.

Given an integer array flowerbed containing 0‘s and 1‘s, where 0 means empty and 1 means not empty, and an integer n, return if n new flowers can be planted in the flowerbed without violating the no-adjacent-flowers rule.

Example:

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Input: flowerbed = [1,0,0,0,1], n = 1
Output: true

Code:

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/**
* @param {number[]} flowerbed
* @param {number} n
* @return {boolean}
*/
var canPlaceFlowers = function(flowerbed, n) {
let availablePlots = 0;
if (flowerbed.length === 1) return flowerbed[0] === 0 ? n <= 1 : n === 0;
for (let i = 0; i < flowerbed.length; i++) {
if (i === 0 && flowerbed[i] === 0 && flowerbed[i + 1] === 0) {
availablePlots++;
flowerbed[i] = 1;
continue;
}
if (i === flowerbed.length - 1 && flowerbed[i - 1] === 0 && flowerbed[i] === 0) {
availablePlots++;
flowerbed[i] = 1;
continue;
}
if (flowerbed[i - 1] === 0 && flowerbed[i] === 0 && flowerbed[i + 1] === 0) {
availablePlots++;
flowerbed[i] = 1;
}
}
return availablePlots >= n;
};