hammingWeight

Author: aouos

README.md

@@ -45,6 +45,7 @@
 | 0160 | [getIntersectionNode](./code/0160_getIntersectionNode) | ⭐ | Linked List | 1️⃣✅ |
 | 0162 | [findPeakElement](./code/0162_findPeakElement) | ⭐⭐ | Array, Binary Search |  |
 | 0189 | [rotate](./code/0189_rotate) | ⭐⭐ | Array |  |
+| 0191 | [hammingWeight](./code/0191_hammingWeight) | ⭐ | Bit | 1️⃣ |
 | 0204 | [countPrimes](./code/0204_countPrimes) | ⭐ | Hash Table |  |
 | 0206 | [reverseList](./code/0206_reverseList) | ⭐ | Linked List |  |
 | 0222 | [countNodes](./code/0222_countNodes) | ⭐⭐ | Tree, Binary Search |  |

code/0191_hammingWeight/hammingWeight.js

@@ -0,0 +1,15 @@
+/**
+ * @param {number} n - a positive integer
+ * @return {number}
+ */
+var hammingWeight = function (n) {
+  let ans = 0;
+  while (n) {
+    n = n & (n - 1);
+    ans++;
+  }
+  return ans;
+};
+
+// 时间复杂度 O(logN)
+// 空间复杂度 O(1)