Given two positive integers n and k, the binary string Sn is formed as follows:
Where + denotes the concatenation operation, reverse(x) returns the reversed string x, and invert(x) inverts all the bits in x (0 changes to 1 and 1 changes to 0).
For example, the first four strings in the above sequence are:
Return the kth bit in Sn. It is guaranteed that k is valid for the given n.
Examples
Example 1
Input: n = 3, k = 1
Output: "0"
Explanation: S3 is "0111001".
The 1st bit is "0".
Example 2
Input: n = 4, k = 11
Output: "1"
Explanation: S4 is "011100110110001".
The 11th bit is "1".
Constraints
1 <= n <= 20
1 <= k <= 2n - 1
1545. Find Kth Bit in Nth Binary String
Medium
30 Points
String
Recursion
Simulation
Given two positive integers n and k, the binary string Sn is formed as follows:
Where + denotes the concatenation operation, reverse(x) returns the reversed string x, and invert(x) inverts all the bits in x (0 changes to 1 and 1 changes to 0).
For example, the first four strings in the above sequence are:
Return the kth bit in Sn. It is guaranteed that k is valid for the given n.
Examples
Example 1
Input: n = 3, k = 1
Output: "0"
Explanation: S3 is "0111001".
The 1st bit is "0".
Example 2
Input: n = 4, k = 11
Output: "1"
Explanation: S4 is "011100110110001".
The 11th bit is "1".
Constraints
1 <= n <= 20
1 <= k <= 2n - 1
Find Kth Bit in Nth Binary String - Practice Coding | SlaveCode