feat: add kotlin solution to lc problem: No.0713

Author: Zuoqiu-Yingyi

solution/0700-0799/0713.Subarray Product Less Than K/README.md

@@ -205,6 +205,26 @@ var numSubarrayProductLessThanK = function (nums, k) {
 };
 ```
 
+#### Kotlin
+
+```kotlin
+class Solution {
+    fun numSubarrayProductLessThanK(nums: IntArray, k: Int): Int {
+        var left = 0
+        var count = 0
+        var product = 1
+        nums.forEachIndexed { right, num ->
+            product *= num
+            while (product >= k && left <= right) {
+                product /= nums[left++]
+            }
+            count += right - left + 1
+        }
+        return count
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

solution/0700-0799/0713.Subarray Product Less Than K/README_EN.md

@@ -186,6 +186,26 @@ var numSubarrayProductLessThanK = function (nums, k) {
 };
 ```
 
+#### Kotlin
+
+```kotlin
+class Solution {
+    fun numSubarrayProductLessThanK(nums: IntArray, k: Int): Int {
+        var left = 0
+        var count = 0
+        var product = 1
+        nums.forEachIndexed { right, num ->
+            product *= num
+            while (product >= k && left <= right) {
+                product /= nums[left++]
+            }
+            count += right - left + 1
+        }
+        return count
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

solution/0700-0799/0713.Subarray Product Less Than K/Solution.kt

@@ -0,0 +1,15 @@
+class Solution {
+    fun numSubarrayProductLessThanK(nums: IntArray, k: Int): Int {
+        var left = 0
+        var count = 0
+        var product = 1
+        nums.forEachIndexed { right, num ->
+            product *= num
+            while (product >= k && left <= right) {
+                product /= nums[left++]
+            }
+            count += right - left + 1
+        }
+        return count
+    }
+}