DaleStudy#233 Counting Bits

Author: forest000014

counting-bits/forest000014.java

@@ -0,0 +1,19 @@
+/*
+# Time Complexity: O(n)
+# Space Complexity: O(1)
+*/
+class Solution {
+    public int[] countBits(int n) {
+        int[] ans = new int[n + 1];
+
+        for (int i = 0; i <= n; i++) {
+            int x = i;
+            while (x > 0) {
+                ans[i] += (x & 1);
+                x >>= 1;
+            }
+        }
+
+        return ans;
+    }
+}