Package g3601_3700.s3614_process_string_with_special_operations_ii

Class Solution

java.lang.Object
g3601_3700.s3614_process_string_with_special_operations_ii.Solution
public class Solution extends Object
3614 - Process String with Special Operations II.

Hard

You are given a string s consisting of lowercase English letters and the special characters: '*', '#', and '%'.

You are also given an integer k.

Build a new string result by processing s according to the following rules from left to right:

  • If the letter is a lowercase English letter append it to result.
  • A '*' removes the last character from result, if it exists.
  • A '#' duplicates the current result and appends it to itself.
  • A '%' reverses the current result.

Return the kth character of the final string result. If k is out of the bounds of result, return '.'.

Example 1:

Input: s = “a#b%*”, k = 1

Output: “a”

Explanation:

is[i]OperationCurrent result
0'a'Append 'a'"a"
1'#'Duplicate result"aa"
2'b'Append 'b'"aab"
3'%'Reverse result"baa"
4'*'Remove the last character"ba"

The final result is "ba". The character at index k = 1 is 'a'.

Example 2:

Input: s = “cd%#*#”, k = 3

Output: “d”

Explanation:

is[i]OperationCurrent result
0'c'Append 'c'"c"
1'd'Append 'd'"cd"
2'%'Reverse result"dc"
3'#'Duplicate result"dcdc"
4'*'Remove the last character"dcd"
5'#'Duplicate result"dcddcd"

The final result is "dcddcd". The character at index k = 3 is 'd'.

Example 3:

Input: s = “z*#”, k = 0

Output: “.”

Explanation:

is[i]OperationCurrent result
0'z'Append 'z'"z"
1'*'Remove the last character""
2'#'Duplicate the string""

The final result is "". Since index k = 0 is out of bounds, the output is '.'.

Constraints:

  • 1 <= s.length <= 105
  • s consists of only lowercase English letters and special characters '*', '#', and '%'.
  • 0 <= k <= 1015
  • The length of result after processing s will not exceed 1015.

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • processStr

      public char processStr(String s, long k)