✨ Counting Bits

README.md

@@ -154,3 +154,4 @@ npm run test
 | 130 |                            [JewelsAndStones](src/jewelsAndStones/index.ts)                            |              [:green_book:](src/jewelsAndStones/README.md)               |    Easy    | [LeetCode](https://leetcode.com/problems/jewels-and-stones)                                 | HashTable |
 | 131 |                         [NumberOfBoomerangs](src/numberOfBoomerangs/index.ts)                         |             [:green_book:](src/numberOfBoomerangs/README.md)             |    Easy    | [LeetCode](https://leetcode.com/problems/number-of-boomerangs)                              | HashTable |
 | 132 |                          [IsomorphicStrings](src/isomorphicStrings/index.ts)                          |             [:green_book:](src/isomorphicStrings/README.md)              |    Easy    | [LeetCode](https://leetcode.com/problems/isomorphic-strings)                                | HashTable |
+| 133 |                               [CountingBits](src/countingBits/index.ts)                               |                [:green_book:](src/countingBits/README.md)                |    Easy    | [LeetCode](https://leetcode.com/problems/counting-bits)                                     | Bit       |

src/countingBits/README.md

@@ -0,0 +1,12 @@
+# 133.Counting Bits
+
+## Description
+
+Given a non negative integer number num. For every numbers i in the range 0 ≤ i ≤ num calculate the number of 1's in their binary representation and return them as an array.
+
+Example:
+For num = 5 you should return [0,1,1,2,1,2].
+
+## From
+
+[LeetCode](https://leetcode.com/problems/counting-bits)

src/countingBits/index.ts

@@ -0,0 +1,20 @@
+export function countBits(num: number) {
+  let res = []
+  let i = 0
+  while (i <= num) {
+    res.push(getBits(i))
+    i++
+  }
+
+  return res
+}
+
+const getBits = (num: number) => {
+  let res = 0
+  while (num > 0) {
+    res += num & 1
+    num >>= 1
+  }
+
+  return res
+}

src/countingBits/test.ts

@@ -0,0 +1,13 @@
+import { countBits } from '.'
+
+test('CountingBits-1', () => {
+  expect(countBits(5)).toEqual([0, 1, 1, 2, 1, 2])
+})
+
+test('CountingBits-2', () => {
+  expect(countBits(6)).toEqual([0, 1, 1, 2, 1, 2, 2])
+})
+
+test('CountingBits-3', () => {
+  expect(countBits(0)).toEqual([0])
+})

src/index.ts

@@ -131,3 +131,4 @@ export * from './sumOfTwoIntegers'
 export * from './jewelsAndStones'
 export * from './numberOfBoomerangs'
 export * from './isomorphicStrings'
+export * from './countingBits'