add Counting Bits solution

Author: HoonDongKang

counting-bits/HoonDongKang.ts

@@ -0,0 +1,32 @@
+/**
+ * [Problem]: [338] Counting Bits
+ * (https://leetcode.com/problems/counting-bits/description/)
+ */
+function countBits(n: number): number[] {
+    //시간복잡도 O(n)
+    //공간복잡도 O(n)
+    function dpFunc(n: number): number[] {
+        const dp = new Array(n + 1).fill(0);
+        let offset = 1;
+
+        for (let i = 1; i <= n; i++) {
+            if (offset * 2 === i) {
+                offset = i;
+            }
+
+            dp[i] = 1 + dp[i - offset];
+        }
+
+        return dp;
+    }
+
+    //시간복잡도 O(n)
+    //공간복잡도 O(n)
+    function optimizedFunc(n: number): number[] {
+        const dp = new Array(n + 1).fill(0);
+        for (let i = 0; i <= n; i++) {
+            dp[i] = dp[i >> 1] + (i & 1);
+        }
+        return dp;
+    }
+}