Package g0701_0800.s0779_k_th_symbol_in_grammar

Class Solution

java.lang.Object
g0701_0800.s0779_k_th_symbol_in_grammar.Solution
public class Solution extends java.lang.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 Summary

    Constructors
    Constructor
    Description
    Solution()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    kthGrammar(int n, int k)
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • kthGrammar

      public int kthGrammar(int n, int k)