LeetCode in Kotlin
1201. Ugly Number III
Medium
An ugly number is a positive integer that is divisible by a, b, or c.
Given four integers n, a, b, and c, return the nth ugly number.
Example 1:
Input: n = 3, a = 2, b = 3, c = 5
Output: 4
Explanation: The ugly numbers are 2, 3, 4, 5, 6, 8, 9, 10… The 3rd is 4.
Example 2:
Input: n = 4, a = 2, b = 3, c = 4
Output: 6
Explanation: The ugly numbers are 2, 3, 4, 6, 8, 9, 10, 12… The 4th is 6.
Example 3:
Input: n = 5, a = 2, b = 11, c = 13
Output: 10
Explanation: The ugly numbers are 2, 4, 6, 8, 10, 11, 12, 13… The 5th is 10.
Constraints:
1 <= n, a, b, c <= 1091 <= a * b * c <= 1018- It is guaranteed that the result will be in range
[1, 2 * 109].
Solution
class Solution {
private fun getLcm(a: Long, b: Long): Long {
var mx = a
var mn = b
if (a < b) {
mx = b
mn = a
}
while (mn != 0L) {
val tmp = mn
mn = mx % mn
mx = tmp
}
return a * b / mx
}
fun nthUglyNumber(n: Int, a: Int, b: Int, c: Int): Int {
val ab = getLcm(a.toLong(), b.toLong())
val ac = getLcm(a.toLong(), c.toLong())
val bc = getLcm(b.toLong(), c.toLong())
val abc = getLcm(a.toLong(), bc)
var left: Long = 1
var right: Long = 2000000001
if (a != 0 && b != 0 && c != 0 && bc != 0L) {
while (left < right) {
val mid = left + (right - left) / 2
if (mid / a + mid / b + mid / c - mid / ab - mid / ac - mid / bc + mid / abc >= n) {
right = mid
} else {
left = mid + 1
}
}
}
return left.toInt()
}
}