605. Can Place Flowers

Suppose 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 - they would compete for water and both would die.

Given a flowerbed (represented as an array containing 0 and 1, where 0 means empty and 1 means not empty), and a number n, return if n new flowers can be planted in it without violating the no-adjacent-flowers rule.

Example 1:

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

Example 2:

Input: flowerbed = [1,0,0,0,1], n = 2
Output: False

Note:

1. The input array won’t violate no-adjacent-flowers rule.

2. The input array size is in the range of [1, 20000].

3. n is a non-negative integer which won’t exceed the input array size.

/**
 * @param {number[]} flowerbed
 * @param {number} n
 * @return {boolean}
 */
var canPlaceFlowers = function(flowerbed, n) {
    if (n < 1) {
        return true;
    }
    const len = flowerbed.length;
    if (n > (parseInt(len / 2) + 1)) {
        return false;
    }
    let current = 0;
    for (let i = 0; i < len; i++) {
        if (flowerbed[i] === 0) {
            if (flowerbed[i - 1] !== 1 && flowerbed[i + 1] !== 1) {
                flowerbed[i] = 1;
                current++;
            }
        }
        if (current >= n) {
            return true;
        }
    }
    return current >= n;
};