Example 1:
Input: ["TextEditor", "addText", "deleteText", "addText", "cursorRight", "cursorLeft", "deleteText", "cursorLeft", "cursorRight"]
[[], ["leetcode"], [4], ["practice"], [3], [8], [10], [2], [6]]
Output: [null, null, 4, null, "etpractice", "leet", 4, "", "practi"]
Explanation:
Design a text editor with a cursor that can insert text, delete text immediately to the left of the cursor, and move the cursor in either direction.
Implement the TextEditor class:
TextEditor() Initializes the editor with empty text.void addText(string text) Inserts text immediately to the left of the cursor. The cursor remains after the inserted text.int deleteText(int k) Deletes up to k characters immediately to the left of the cursor and returns the number deleted.string cursorLeft(int k) Moves the cursor up to k positions left and returns the last at most 10 characters to the left of the cursor.string cursorRight(int k) Moves the cursor up to k positions right and returns the last at most 10 characters to the left of the cursor.After inserting leetcode, four characters are deleted. Inserting practice produces leetpractice|. Moving and deleting around the cursor yields the returned previews shown above.
1 <= text.length, k <= 40text consists of lowercase English letters.addText is at most 4 * 10^5.k values passed to cursor and delete operations is at most 4 * 10^5.