摘要：
Description When a radio station is broadcasting over a very large area, repeaters are used to retransmit the signal so that every receiver has a stro 阅读全文
摘要：
Description Sudoku is a very simple task. A square table with 9 rows and 9 columns is divided to 9 smaller squares 3x3 as shown on the Figure. In some 阅读全文