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How to Solve Concatenation of Consecutive Binary Numbers Problem

Master the Concatenation of Consecutive Binary Numbers LeetCode problem with undetectable real-time assistance. Get instant solutions and explanations during your coding interviews.

Phantom Code generates complete solutions and debugging hints that you can use while explaining your approach, so you stay calm and in control.

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Medium#1680

LeetCode Problem

Concatenation of Consecutive Binary Numbers

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.

MathBit ManipulationSimulation

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Problem Breakdown

Understanding the Concatenation of Consecutive Binary Numbers Problem

Let's break down this LeetCode problem and understand what makes it challenging in interview settings.

Problem Statement

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.

MediumProblem #1680

LeetCode

Concatenation of Consecutive Binary Numbers

How Phantom Code Helps

Get real-time assistance for Concatenation of Consecutive Binary Numbers problems during coding interviews. Phantom Code provides instant solutions and explanations.

Examples

# Example 1

Input

n = 1

Output

# Example 2

Input

n = 3

Output

# Example 3

Input

n = 12

Output

505379714

Constraints

1 <= n <= 105

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Solve Concatenation of Consecutive Binary Numbers — Given an integer n, return the decimal value of the binary string formed by conc...

Here's the optimal approach using Math:

def solve(input):

# Optimal O(n) solution

return result

Time: O(n) | Space: O(n)

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Frequently Asked Questions

Common questions about solving Concatenation of Consecutive Binary Numbers and using Phantom Code during coding interviews.

How does Phantom Code help me solve coding problems like Concatenation of Consecutive Binary Numbers during interviews?

Phantom Code generates complete solutions instantly with proper complexity analysis, letting you focus on explaining your approach and demonstrating problem-solving skills rather than getting stuck on implementation details during high-pressure situations.

What if the interviewer asks follow-up questions or modifications to problems like Concatenation of Consecutive Binary Numbers?

Phantom Code adapts in real-time. Screenshot the modified problem or use audio mode to capture the interviewer's follow-up, and get an updated solution within seconds — including edge cases and optimizations.

Can Phantom Code help me communicate my solution for problems like Concatenation of Consecutive Binary Numbers?

Yes. Phantom Code provides step-by-step approach explanations with 3 progressive thoughts, so you can walk through your solution naturally. It also provides time and space complexity analysis to discuss trade-offs.

How does Phantom Code assist with different programming languages for Concatenation of Consecutive Binary Numbers type problems?

Phantom Code supports 11 programming languages including Python, Java, C++, JavaScript, TypeScript, Go, Rust, Ruby, Swift, Kotlin, and C#. Set your preferred language and get idiomatic solutions.

What coding mistakes does Phantom Code help me avoid during Concatenation of Consecutive Binary Numbers interviews?

Phantom Code catches common mistakes like off-by-one errors, missing edge cases, incorrect base conditions, and suboptimal approaches. It provides clean, well-structured code that handles all edge cases.

Is Phantom Code detectable when solving problems like Concatenation of Consecutive Binary Numbers during live interviews?

No. Phantom Code runs as an invisible desktop overlay that doesn't appear in screen shares, recordings, or proctoring software. It works with Zoom, HackerRank, CodeSignal, CoderPad, and all major platforms.

How does Phantom Code help when I'm struggling with Concatenation of Consecutive Binary Numbers style questions under pressure?

The AI provides structured guidance: first the approach (what algorithm/data structure to use and why), then the implementation with clean code, and finally complexity analysis. This helps you think clearly even under pressure.

Does Phantom Code work for the coding platforms used in Concatenation of Consecutive Binary Numbers interviews?

Yes. Phantom Code works with all major coding platforms including LeetCode, HackerRank, CodeSignal, CoderPad, HackerEarth, and any browser-based coding environment.

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