Medium
There is a special kind of apple tree that grows apples every day for n
days. On the ith
day, the tree grows apples[i]
apples that will rot after days[i]
days, that is on day i + days[i]
the apples will be rotten and cannot be eaten. On some days, the apple tree does not grow any apples, which are denoted by apples[i] == 0
and days[i] == 0
.
You decided to eat at most one apple a day (to keep the doctors away). Note that you can keep eating after the first n
days.
Given two integer arrays days
and apples
of length n
, return the maximum number of apples you can eat.
Example 1:
Input: apples = [1,2,3,5,2], days = [3,2,1,4,2]
Output: 7
Explanation: You can eat 7 apples:
On the first day, you eat an apple that grew on the first day.
On the second day, you eat an apple that grew on the second day.
On the third day, you eat an apple that grew on the second day. After this day, the apples that grew on the third day rot.
On the fourth to the seventh days, you eat apples that grew on the fourth day.
Example 2:
Input: apples = [3,0,0,0,0,2], days = [3,0,0,0,0,2]
Output: 5
Explanation: You can eat 5 apples:
On the first to the third day you eat apples that grew on the first day.
Do nothing on the fouth and fifth days.
On the sixth and seventh days you eat apples that grew on the sixth day.
Constraints:
n == apples.length == days.length
1 <= n <= 2 * 104
0 <= apples[i], days[i] <= 2 * 104
days[i] = 0
if and only if apples[i] = 0
.import java.util.PriorityQueue
class Solution {
fun eatenApples(apples: IntArray, days: IntArray): Int {
val minHeap = PriorityQueue { a: IntArray, b: IntArray -> a[0] - b[0] }
var eatenApples = 0
var i = 0
while (i < apples.size || minHeap.isNotEmpty()) {
if (i < apples.size) {
minHeap.offer(intArrayOf(i + days[i], apples[i]))
}
while (minHeap.isNotEmpty() && (minHeap.peek()[0] <= i || minHeap.peek()[1] <= 0)) {
minHeap.poll()
}
if (minHeap.isNotEmpty()) {
eatenApples++
minHeap.peek()[1]--
}
i++
}
return eatenApples
}
}