K-th Symbol in Grammar Problem

K-th Symbol in Grammar Problem — ExecCode Medium DSA Practice

Solve the K-th Symbol in Grammar problem on ExecCode. Free online medium DSA practice in Math. Write and run code in Java, C++, Python — no signup required to run.

Problem description

Description We build a table of n rows (1-indexed). We start by writing 0 in the 1^st row. Now in every subsequent row, we look at the previous row and replace each occurrence of 0 with 01, and each occurrence of 1 with 10. For example, for n = 3, the 1^st row is 0, the 2^nd row is 01, and the 3^rd row is 0110. Given two integer n and k, return the k^th (1-indexed) symbol in the n^th row of a table of n rows. Examples Example 1 Input: n = 1, k = 1 Output: 0 Explanation: row 1: 0 Example 2 Input: n = 2, k = 1 Output: 0 Explanation: row 1: 0 row 2: 0 1 Example 3 Input: n = 2, k = 2 Output: 1 Explanation: row 1: 0 row 2: 0 1 Constraints 1 <= n <= 30 1 <= k <= 2^n - 1

Examples

Input {"n": 1, "k": 1}; Output 0. Input {"n": 2, "k": 1}; Output 0. Input {"n": 2, "k": 2}; Output 1

Constraints

1 <= n <= 30 1 <= k <= 2^n - 1

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