LeetCode in Kotlin

670. Maximum Swap

Medium

You are given an integer num. You can swap two digits at most once to get the maximum valued number.

Return the maximum valued number you can get.

Example 1:

Input: num = 2736

Output: 7236

Explanation: Swap the number 2 and the number 7.

Example 2:

Input: num = 9973

Output: 9973

Explanation: No swap.

Constraints:

Solution

class Solution {
    fun maximumSwap(num: Int): Int {
        val chars = num.toString().toCharArray()
        for (i in chars.indices) {
            var j = chars.size - 1
            var indx = i
            var c = chars[i]
            while (j > i) {
                if (chars[j] > c) {
                    c = chars[j]
                    indx = j
                }
                j--
            }
            if (indx != i) {
                val temp = chars[i]
                chars[i] = chars[indx]
                chars[indx] = temp
                return String(chars).toInt()
            }
        }
        return num
    }
}