문제
A "0/1 string" is a string in which every character is either 0 or 1. There are two operations that can be performed on a 0/1 string:
- switch: Every
0becomes1and every1becomes0. For example, "100" becomes "011". - reverse: The string is reversed. For example, "100" becomes "001".
Consider this infinite sequence of 0/1 strings:
- S0 = ""
- S1 = "0"
- S2 = "001"
- S3 = "0010011"
- S4 = "001001100011011"
- ...
- SN = SN-1 + "0" + switch(reverse(SN-1)).
You need to figure out the Kth character of Sgoogol, where googol = 10100.