Decoded String at Index
You are given an encoded string s. To decode the string to a tape, the encoded string is read one character at a time and the following steps are taken:
- If the character read is a letter, that letter is written onto the tape.
- If the character read is a digit
d, the entire current tape is repeatedly writtend - 1more times in total.
Given an integer k, return the k^th letter (1-indexed) in the decoded string.
Example 1
Input
s = "leet2code3", k = 10Output
"o"The decoded string is "leetleetcodeleetleetcodeleetleetcode", and the 10th letter is "o".
Example 2
Input
s = "ha22", k = 5Output
"h"The decoded string is "hahahaha", and the 5th letter is "h".
Constraints
- 2 <= s.length <= 100
- s consists of lowercase English letters and digits 2 through 9.
- s starts with a letter.
- 1 <= k <= 10^9
- It is guaranteed that k is less than or equal to the length of the decoded string.
- The decoded string is guaranteed to have less than 2^63 letters.