LeetCode in Kotlin

2933. High-Access Employees

Medium

You are given a 2D 0-indexed array of strings, access_times, with size n. For each i where 0 <= i <= n - 1, access_times[i][0] represents the name of an employee, and access_times[i][1] represents the access time of that employee. All entries in access_times are within the same day.

The access time is represented as four digits using a 24-hour time format, for example, "0800" or "2250".

An employee is said to be high-access if he has accessed the system three or more times within a one-hour period.

Times with exactly one hour of difference are not considered part of the same one-hour period. For example, "0815" and "0915" are not part of the same one-hour period.

Access times at the start and end of the day are not counted within the same one-hour period. For example, "0005" and "2350" are not part of the same one-hour period.

Return a list that contains the names of high-access employees with any order you want.

Example 1:

Input: access_times = [[“a”,”0549”],[“b”,”0457”],[“a”,”0532”],[“a”,”0621”],[“b”,”0540”]]

Output: [“a”]

Explanation: “a” has three access times in the one-hour period of [05:32, 06:31] which are 05:32, 05:49, and 06:21. But “b” does not have more than two access times at all. So the answer is [“a”].

Example 2:

Input: access_times = [[“d”,”0002”],[“c”,”0808”],[“c”,”0829”],[“e”,”0215”],[“d”,”1508”],[“d”,”1444”],[“d”,”1410”],[“c”,”0809”]]

Output: [“c”,”d”]

Explanation: “c” has three access times in the one-hour period of [08:08, 09:07] which are 08:08, 08:09, and 08:29. “d” has also three access times in the one-hour period of [14:10, 15:09] which are 14:10, 14:44, and 15:08. However, “e” has just one access time, so it can not be in the answer and the final answer is [“c”,”d”].

Example 3:

Input: access_times = [[“cd”,”1025”],[“ab”,”1025”],[“cd”,”1046”],[“cd”,”1055”],[“ab”,”1124”],[“ab”,”1120”]]

Output: [“ab”,”cd”]

Explanation: “ab” has three access times in the one-hour period of [10:25, 11:24] which are 10:25, 11:20, and 11:24. “cd” has also three access times in the one-hour period of [10:25, 11:24] which are 10:25, 10:46, and 10:55. So the answer is [“ab”,”cd”].

Constraints:

Solution

class Solution {
    private fun isPossible(a: Int, b: Int): Boolean {
        val hb = b / 100
        val ha = a / 100
        var mind = b % 100
        val mina = a % 100
        if (hb == 23 && ha == 0) {
            return false
        }
        if (hb - ha > 1) {
            return false
        }
        if (hb - ha == 1) {
            mind += 60
        }
        return mind - mina < 60
    }

    private fun isHighAccess(list: List<Int>): Boolean {
        if (list.size < 3) {
            return false
        }
        var i = 0
        var j = 1
        var k = 2
        while (k < list.size) {
            val a = list[i++]
            val b = list[j++]
            val c = list[k++]
            if (isPossible(a, c) && isPossible(b, c) && isPossible(a, b)) {
                return true
            }
        }
        return false
    }

    private fun stringToInt(str: String): Int {
        var i = 1000
        var `val` = 0
        for (ch in str.toCharArray()) {
            val n = ch.code - '0'.code
            `val` += i * n
            i = i / 10
        }
        return `val`
    }

    fun findHighAccessEmployees(accessTimes: List<List<String>>): List<String> {
        val map = HashMap<String, MutableList<Int>>()
        for (list in accessTimes) {
            val temp = map.getOrDefault(list[0], ArrayList())
            val `val` = stringToInt(list[1])
            temp.add(`val`)
            map[list[0]] = temp
        }
        val ans: MutableList<String> = ArrayList()
        for ((key, temp) in map) {
            temp.sort()
            if (isHighAccess(temp)) {
                ans.add(key)
            }
        }
        return ans
    }
}