1705 - Maximum Number of Eaten Apples.

Medium

There is a special kind of apple tree that grows apples every day for n days. On the <code>i^th</code> 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

• <code>1 <= n <= 2 * 10⁴</code>

• <code>0 <= applesi, daysi<= 2 * 10⁴</code>

• days[i] = 0 if and only if apples[i] = 0.