Can Place Flowers
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.
package questions
import _utils.UseCommentAsDocumentation
import utils.shouldBe
/**
* 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.
*
* [Source](https://leetcode.com/problems/can-place-flowers/)
*/
@UseCommentAsDocumentation
private fun canPlaceFlowers(flowerbed: IntArray, n: Int): Boolean {
if (flowerbed.size < n) {
return false
}
var remaining = n
var current = 0
while (current <= flowerbed.lastIndex && remaining > 0) {
val isEmpty = flowerbed[current] == 0
if (!isEmpty) {
current += 2
continue
} else {
val prevPlot = flowerbed.getOrNull(current - 1)
val nextPlot = flowerbed.getOrNull(current + 1)
if ((nextPlot == null || nextPlot == 0) && (prevPlot == null || prevPlot == 0)) {
remaining--
flowerbed[current] = 1
current += 2
continue
}
}
current++
}
return remaining == 0
}
fun main() {
canPlaceFlowers(flowerbed = intArrayOf(0, 0, 1, 0, 0), n = 1) shouldBe true
canPlaceFlowers(flowerbed = intArrayOf(0, 0, 0, 0, 0, 0, 0), n = 4) shouldBe true
canPlaceFlowers(flowerbed = intArrayOf(1, 0, 1, 0, 1), n = 1) shouldBe false
canPlaceFlowers(flowerbed = intArrayOf(1, 0, 0, 0, 1), n = 1) shouldBe true
canPlaceFlowers(flowerbed = intArrayOf(1, 0, 0, 0, 1), n = 2) shouldBe false
}
Updated on 2021-11-13