add: numberOf1Bits solution

Author: Cyjin-jani

number-of-1-bits/Cyjin-jani.js

@@ -0,0 +1,29 @@
+// tc: O(logn)
+// sc: O(logn)
+const hammingWeight_simple = function (n) {
+  const binaryStr = n.toString(2);
+  let answer = 0;
+
+  for (char of binaryStr) {
+    if (+char === 1) {
+      answer++;
+    }
+  }
+
+  return answer;
+};
+
+// toString(2)를 쓰지 않고 처리
+// tc: O(logn)
+// sc: O(1)
+const hammingWeight = function (n) {
+  let answer = 0;
+
+  while (n >= 0) {
+    const remains = n % 2;
+    if (remains === 1) answer++;
+    n = Math.floor(n / 2);
+  }
+
+  return answer;
+};