Medium
You are given an integer array ranks
representing the ranks of some mechanics. ranksi is the rank of the ith mechanic. A mechanic with a rank r
can repair n cars in r * n2
minutes.
You are also given an integer cars
representing the total number of cars waiting in the garage to be repaired.
Return the minimum time taken to repair all the cars.
Note: All the mechanics can repair the cars simultaneously.
Example 1:
Input: ranks = [4,2,3,1], cars = 10
Output: 16
Explanation:
The first mechanic will repair two cars. The time required is 4 * 2 * 2 = 16 minutes.
The second mechanic will repair two cars. The time required is 2 * 2 * 2 = 8 minutes.
The third mechanic will repair two cars. The time required is 3 * 2 * 2 = 12 minutes.
The fourth mechanic will repair four cars. The time required is 1 * 4 * 4 = 16 minutes.
It can be proved that the cars cannot be repaired in less than 16 minutes.
Example 2:
Input: ranks = [5,1,8], cars = 6
Output: 16
Explanation:
The first mechanic will repair one car. The time required is 5 * 1 * 1 = 5 minutes.
The second mechanic will repair four cars. The time required is 1 * 4 * 4 = 16 minutes.
The third mechanic will repair one car. The time required is 8 * 1 * 1 = 8 minutes.
It can be proved that the cars cannot be repaired in less than 16 minutes.
Constraints:
1 <= ranks.length <= 105
1 <= ranks[i] <= 100
1 <= cars <= 106
@Suppress("NAME_SHADOWING")
class Solution {
fun repairCars(ranks: IntArray, cars: Int): Long {
ranks.sort()
var low: Long = 0
var hi = Long.MAX_VALUE
var ans: Long = -1
while (low <= hi) {
val mid = (low + hi) / 2
if (isPossible(mid, ranks, cars)) {
hi = mid - 1
ans = mid
} else {
low = mid + 1
}
}
return ans
}
private fun isPossible(target: Long, ranks: IntArray, cars: Int): Boolean {
var cars = cars
for (i in ranks.indices) {
cars -= Math.sqrt((target / ranks[i]).toDouble()).toInt()
if (cars <= 0) {
return true
}
}
return false
}
}