#329 Counting Bits

easy
javascript
blind75
bit-manipulation
dynamic-programming

Given an integer n, return an array where output[i] is the number of 1's in the binary representation of i for all numbers from 0 to n.

Rules:

  • Return array of length n+1
  • Each element represents count of 1's in binary form of index
  • Array starts from 0 and goes up to n

Constraints:

  • 0 ≤ n ≤ 1000

Examples:

// Example 1:

console.log(countBits(4));
// Output: [0,1,1,2,1]

// Explanation:

// 0 -> 0     -> 0 ones

// 1 -> 1     -> 1 one

// 2 -> 10    -> 1 one

// 3 -> 11    -> 2 ones

// 4 -> 100   -> 1 one