Easy1323 challenge

Author: konstantin

src/easy/1323. Maximum 69 Number .kt

@@ -0,0 +1,32 @@
+package easy
+
+import GreedyTopic
+import MathTopic
+
+/**
+ * 1323. Maximum 69 Number
+ * https://leetcode.com/problems/maximum-69-number/
+ *
+You are given a positive integer num consisting only of digits 6 and 9.
+Return the maximum number you can get by changing at most one digit (6 becomes 9, and 9 becomes 6).
+ */
+
+class Easy1323 : MathTopic, GreedyTopic {
+
+    fun maximum69Number(num: Int): Int {
+        val arr = num.toString().toCharArray()
+        for (i in arr.indices) {
+            if (arr[i] == '6') {
+                arr[i] = '9'
+                return String(arr).toInt()
+            }
+        }
+        return num
+    }
+}
+
+fun main() {
+    println(Easy1323().maximum69Number(9669))
+    println(Easy1323().maximum69Number(9996))
+    println(Easy1323().maximum69Number(9999))
+}