You are writing a simple text editor that supports only the following two commands:
All quotes are for clarity only. The text in the editor is initially empty.
For example, consider the following sequence of commands:
Second 1: type a Second 2: type b Second 3: type c Second 5: undo 3
At the end of second 3, the text is "abc". At second 5, all commands performed in the previous 3 seconds are undone in reverse order. This means 'c' is removed, and then 'b' is removed. The text becomes just "a".
Note that "undo" commands can also be undone. For example:
Second 1: type a Second 2: type b Second 3: undo 2 Second 4: undo 2
After second 2, the text is "ab". After second 3, everything is undone, and the text becomes empty. At second 4, the previous "undo" is undone, so the text becomes "ab" again. Then, the "type b" is also undone and the text becomes just "a".
You are given a String commands and a int time. Each element of commands is a single command, and commands[i] is performed at time[i]. The commands are given in chronological order. Return the text after all the commands are executed.
|-||commands will contain between 1 and 50 elements, inclusive.|
|-||Each element of commands will be either "type c" where c is a lowercase letter ('a'-'z') or "undo t" where t is an integer between 1 and 10^9, inclusive, with no leading zeroes (quotes for clarity only).|
|-||time will contain the same number of elements as commands.|
|-||Each element of time will be between 1 and 10^9, inclusive.|
|-||The elements of time will be in strictly ascending order.|