add kotlin solution for 338 Counting-Bits.kt

Author: MagicienDeCode

May-LeetCoding-Challenge/28-Counting-Bits/Counting-Bits.kt

@@ -0,0 +1,43 @@
+class CountingBitsKotlin338 {
+    /*
+    0 -> 0
+    1 -> 1
+
+    2 -> 1
+    3 -> 2
+
+    4 -> 1
+    5 -> 2
+    6 -> 2
+    7 -> 3
+     */
+    fun countBits(num: Int): IntArray {
+        val result = IntArray(num + 1)
+        for (index in result.indices) {
+            result[index] = result[index.shr(1)] + if (index % 2 == 0) 0 else 1
+        }
+        return result
+    }
+
+    /*
+    fun countBits(num: Int): IntArray {
+        return IntRange(0, num).map(this::bitCountOne).toIntArray()
+    }
+
+    private fun bitCountOne(target: Int): Int {
+        var count = 0
+        var n = target
+        while (n != 0) {
+            count += n % 2
+            n /= 2
+        }
+        return count
+    }
+     */
+}
+
+fun main() {
+    val solution = CountingBitsKotlin338()
+    // 0 1 1 2 1 2
+    solution.countBits(5).forEach(::print)
+}