Hard
There are n
oranges in the kitchen and you decided to eat some of these oranges every day as follows:
n
is divisible by 2
then you can eat n / 2
oranges.n
is divisible by 3
then you can eat 2 * (n / 3)
oranges.You can only choose one of the actions per day.
Given the integer n
, return the minimum number of days to eat n
oranges.
Example 1:
Input: n = 10
Output: 4
Explanation: You have 10 oranges.
Day 1: Eat 1 orange, 10 - 1 = 9.
Day 2: Eat 6 oranges, 9 - 2*(9/3) = 9 - 6 = 3. (Since 9 is divisible by 3)
Day 3: Eat 2 oranges, 3 - 2*(3/3) = 3 - 2 = 1.
Day 4: Eat the last orange 1 - 1 = 0.
You need at least 4 days to eat the 10 oranges.
Example 2:
Input: n = 6
Output: 3
Explanation: You have 6 oranges.
Day 1: Eat 3 oranges, 6 - 6/2 = 6 - 3 = 3. (Since 6 is divisible by 2).
Day 2: Eat 2 oranges, 3 - 2*(3/3) = 3 - 2 = 1. (Since 3 is divisible by 3)
Day 3: Eat the last orange 1 - 1 = 0.
You need at least 3 days to eat the 6 oranges.
Constraints:
1 <= n <= 2 * 109
class Solution {
fun minDays(n: Int): Int {
return eat(n, HashMap())
}
private fun eat(n: Int, cache: MutableMap<Int, Int>): Int {
if (n <= 1) {
return n
}
val cached = cache[n]
if (cached != null) {
return cached
}
val result = (n % 2 + eat(n / 2, cache)).coerceAtMost(n % 3 + eat(n / 3, cache)) + 1
cache[n] = result
return result
}
}