Add a solution for the April 15th challendge.

Author: alexey-agafonov

30-days-leetcoding-challenge/April 15/src/Solution.kt

@@ -0,0 +1,29 @@
+class Solution {
+    fun productExceptSelf(nums: IntArray): IntArray {
+        val left = IntArray(nums.size)
+        val right = IntArray(nums.size)
+        val result = IntArray(nums.size)
+
+        left[0] = 1
+        for (i in 1 until nums.size) {
+            left[i] = left[i - 1] * nums[i - 1]
+        }
+
+        right[nums.size - 1] = 1
+        for (i in nums.size - 2 downTo 0) {
+            right[i] = right[i + 1] * nums[i + 1]
+        }
+
+        for (i in nums.indices) {
+            result[i] = left[i] * right[i]
+        }
+
+        return result
+    }
+}
+
+fun main() {
+    val solution = Solution()
+    val result = solution.productExceptSelf(intArrayOf(2, 3, 4, 5))
+    result.forEach { println(it) }
+}

30-days-leetcoding-challenge/README.md

@@ -16,7 +16,7 @@
 |  April 12  | [Last Stone Weight](https://leetcode.com/explore/featured/card/30-day-leetcoding-challenge/529/week-2/3297/)                   | [Solution.kt](https://github.com/alexey-agafonov/leetcode/tree/master/30-days-leetcoding-challenge/April%2012/src/Solution.kt) |
 |  April 13  | [Contiguous Array](https://leetcode.com/explore/featured/card/30-day-leetcoding-challenge/529/week-2/3298/)                    | [Solution.kt](https://github.com/alexey-agafonov/leetcode/tree/master/30-days-leetcoding-challenge/April%2013/src/Solution.kt) |
 |  April 14  | [Perform String Shifts](https://leetcode.com/explore/featured/card/30-day-leetcoding-challenge/529/week-2/3299/)               | [Solution.kt](https://github.com/alexey-agafonov/leetcode/tree/master/30-days-leetcoding-challenge/April%2014/src/Solution.kt) |
-|  April 15  | | |
+|  April 15  | [Product of Array Except Self](https://leetcode.com/explore/featured/card/30-day-leetcoding-challenge/530/week-3/3300/)        | [Solution.kt](https://github.com/alexey-agafonov/leetcode/tree/master/30-days-leetcoding-challenge/April%2015/src/Solution.kt) |
 |  April 16  | | |
 |  April 17  | | |
 |  April 18  | | |

README.md

@@ -33,7 +33,7 @@ Versions of used programming languages:
 |  April 12  | [Last Stone Weight](https://leetcode.com/explore/featured/card/30-day-leetcoding-challenge/529/week-2/3297/)                   | [Solution.kt](https://github.com/alexey-agafonov/leetcode/tree/master/30-days-leetcoding-challenge/April%2012/src/Solution.kt) |
 |  April 13  | [Contiguous Array](https://leetcode.com/explore/featured/card/30-day-leetcoding-challenge/529/week-2/3298/)                    | [Solution.kt](https://github.com/alexey-agafonov/leetcode/tree/master/30-days-leetcoding-challenge/April%2013/src/Solution.kt) |
 |  April 14  | [Perform String Shifts](https://leetcode.com/explore/featured/card/30-day-leetcoding-challenge/529/week-2/3299/)               | [Solution.kt](https://github.com/alexey-agafonov/leetcode/tree/master/30-days-leetcoding-challenge/April%2014/src/Solution.kt) |
-|  April 15  | | |
+|  April 15  | [Product of Array Except Self](https://leetcode.com/explore/featured/card/30-day-leetcoding-challenge/530/week-3/3300/)        | [Solution.kt](https://github.com/alexey-agafonov/leetcode/tree/master/30-days-leetcoding-challenge/April%2015/src/Solution.kt) |
 |  April 16  | | |
 |  April 17  | | |
 |  April 18  | | |