摘要：
The count-and-say sequence is the sequence of integers beginning as follows:1, 11, 21, 1211, 111221, ... 1 is read off as "one 1" or 11.11 is read off 阅读全文
摘要：
题目： Determine if a Sudoku is valid, according to: Sudoku Puzzles - The Rules. The Sudoku board could be partially filled, where empty cells are filled 阅读全文