Concatenation of Consecutive Binary Numbers — LeetCode 1680 Python Solution
MediumBit ManipulationMathSimulation
- Problem
- #1680
- Pattern
- Bit Manipulation
- Reading time
- 2 min
- Source
- leetcode.com
The problem
Given an integer n, return the decimal value of the binary string formed by concatenating the binary representations of 1 to n in order, modulo 109 + 7.
Example
- Input
- n = 1
- Output
- 1
- Explanation
- "1" in binary corresponds to the decimal value 1.
Python solution
Python
class Solution:
def concatenatedBinary(self, n: int) -> int:
mod = 10**9 + 7
ans = 0
for i in range(1, n + 1):
ans = (ans << i.bit_length() | i) % mod
return ansComplexity
| Measure | Complexity |
|---|---|
| Time | O(n), where n is the given integer |
| Space | O(1) auxiliary |
Pattern: Bit Manipulation
Use XOR, masks and the low-bit trick to replace whole data structures with an integer. LeetCode 1680. Concatenation of Consecutive Binary Numbers is filed here on both counts: the reference solution below belongs to the algorithm family this hub collects, and LeetCode tags it Bit Manipulation.
The bit manipulation guide has the Python template for the pattern and the 194 LeetCode problems that use it.
Related problems
Frequently asked questions
- How hard is LeetCode 1680. Concatenation of Consecutive Binary Numbers?
- LeetCode 1680. Concatenation of Consecutive Binary Numbers is rated Medium on LeetCode.
- What is the time complexity of LeetCode 1680. Concatenation of Consecutive Binary Numbers?
- The Python solution on this page runs in O(n), where n is the given integer.
- What is the space complexity of LeetCode 1680. Concatenation of Consecutive Binary Numbers?
- The Python solution on this page uses O(1) auxiliary space.
- What topics does LeetCode 1680. Concatenation of Consecutive Binary Numbers cover?
- LeetCode 1680. Concatenation of Consecutive Binary Numbers is tagged Bit Manipulation, Math and Simulation on LeetCode.