README.md

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.

Solutions (Rust)

1. Count Continuous Zeroes

impl Solution {
    pub fn can_place_flowers(flowerbed: Vec<i32>, n: i32) -> bool {
        let mut n = n;
        let mut zeroes = 1;

        for i in flowerbed {
            if i == 0 {
                zeroes += 1;
            } else {
                n -= (zeroes - 1) / 2;
                zeroes = 0;
            }
        }

        zeroes += 1;
        n -= (zeroes - 1) / 2;

        n <= 0
    }
}

2. Simulation

impl Solution {
    pub fn can_place_flowers(flowerbed: Vec<i32>, n: i32) -> bool {
        let mut n = n;
        let mut flowerbed = flowerbed;
        flowerbed.insert(0, 0);
        flowerbed.push(0);

        for i in 1..(flowerbed.len() - 1) {
            if flowerbed[i - 1] + flowerbed[i] + flowerbed[i + 1] == 0 {
                flowerbed[i] = 1;
                n -= 1;
            }
        }

        n <= 0
    }
}