#1680

Concatenation of Consecutive Binary Numbers

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Description

Given an integer n, form a binary string by concatenating the binary representations of 1, 2, ..., n in order. Return the decimal value of this binary string modulo 10⁹ + 7.

Example 1:

Input: n = 1

Output: 1

Explanation: "1" in binary corresponds to the decimal value 1.

Example 2:

Input: n = 3

Output: 27

Explanation: In binary, 1, 2, and 3 corresponds to "1", "10", and "11".

After concatenating them, we have "11011", which corresponds to the decimal value 27.

Example 3:

Input: n = 12

Output: 505379714

Explanation: The concatenation results in "1101110010111011110001001101010111100".

The decimal value of that is 118505380540.

After modulo 109 + 7, the result is 505379714.

Code

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class Solution:
    def concatenatedBinary(self, n: int) -> int:

class Solution:
    def concatenatedBinary(self, n: int) -> int: