0605 - Can Place Flowers

Description (leetcode)

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 true if n new flowers can be planted in the flowerbed without violating the no-adjacent-flowers rule and false otherwise.

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

submission

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impl Solution {
    pub fn can_place_flowers(mut flowerbed: Vec<i32>, n: i32) -> bool {
        // this is a more idiomatic Rust solution, however this insertion is expensive
        // flowerbed.insert(0, 0);
        // flowerbed.push(0);
        // flowerbed
        //     .chunk_by(|&a, &b| a == b)
        //     .map(|chunk| (chunk.len() as i32 - 1) / 2)
        //     .sum::<i32>()
        //     >= n

        let len = flowerbed.len();
        let mut planted = 0;

        (0..len).any(|i| {
            if flowerbed[i] == 0
                && (i == 0 || flowerbed[i - 1] == 0)
                && (i + 1 == len || flowerbed[i + 1] == 0)
            {
                flowerbed[i] = 1;
                planted += 1;
            }
            planted >= n
        })
    }
}