Class Solution


  • public class Solution
    extends Object
    779 - K-th Symbol in Grammar.

    Medium

    We build a table of n rows ( 1-indexed ). We start by writing 0 in the 1st 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 1st row is 0, the 2nd row is 01, and the 3rd row is 0110.

    Given two integer n and k, return the kth ( 1-indexed ) symbol in the nth row of a table of n rows.

    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: 01

    Example 3:

    Input: n = 2, k = 2

    Output: 1

    Explanation: row 1: 0 row 2: 01

    Constraints:

    • 1 <= n <= 30
    • 1 <= k <= 2n - 1
    • Constructor Detail

      • Solution

        public Solution()
    • Method Detail

      • kthGrammar

        public int kthGrammar​(int n,
                              int k)