605.Can Place Flowers

tags: Easy,Array,Greedy

605. Can Place Flowers

題目描述

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.

範例

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

Constraints:

• 1 <= flowerbed.length <= 2 * 10⁴
• flowerbed[i] is 0 or 1.
• There are no two adjacent flowers in flowerbed.
• 0 <= n <= flowerbed.length

解答

Python

class Solution:
    def canPlaceFlowers(self, flowerbed: List[int], n: int) -> bool:
        cnt = 0
        for i in range(len(flowerbed)):
            if flowerbed[i] == 0:
                empty_left_plot = (i == 0) or (flowerbed[i - 1] == 0)
                empty_right_plot = (i == len(flowerbed) - 1) or (flowerbed[i + 1] == 0)
                
                if empty_left_plot and empty_right_plot:
                    flowerbed[i] = 1
                    cnt += 1
                    if cnt >= n:
                        return True
                    
        return cnt >= n

Ron ChenMon, Mar 20, 2023

Javascript

function canPlaceFlowers(flowerbed, n) {
  let count = 0;
  for (let i = 0; i < flowerbed.length; i++) {
    if (!flowerbed[i - 1] && !flowerbed[i] && !flowerbed[i + 1]) {
      count++;
      flowerbed[i] = 1;
    }
  }

  if (count >= n) return true;

  return false;
}

MarsgoatMon, Mar 20, 2023

Reference

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