Counting Bits solution

Author: kim-young

counting-bits/kimyoung.js

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+var countBits = function (n) {
+  let result = [];
+  for (let i = 0; i <= n; i++) {
+    result.push(countOneBits(i));  // count one bits for each i until n
+  }
+
+  function countOneBits(num) { // method to count one bits
+    let oneBitCount = 0;
+    while (num) {
+      oneBitCount += num % 2;
+      num = num >> 1;
+    }
+    return oneBitCount;
+  }
+
+  return result;
+};
+
+// test cases
+console.log(countBits(2)); // [0,1,1]
+console.log(countBits(5)); // [0,1,1,2,1,2]
+
+// time - O(nlogn) 
+// space - O(n)