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.
Given two integer n and k, return the kth (1-indexed) symbol in the nth 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: 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
779. K-th Symbol in Grammar
Medium
30 Points
Math
Bit Manipulation
Recursion
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.
Given two integer n and k, return the kth (1-indexed) symbol in the nth 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: 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
K-th Symbol in Grammar - Practice Coding | SlaveCode