摘要：Problem Description Last year summer Max straveled to California for his vacation. He had a great time there: took many photos, visited famous universities, enjoyed beatiful beaches and tasted various... 阅读全文

摘要：Problem Description There is a matrix of size R rows by C columns. Each element in the matrix is either '0' or '1'. A square is called magic square if it meets the following three conditions.The eleme... 阅读全文

摘要：描述 The magician shuffles a small pack of cards, holds it face down and performs the following procedure: This impressive trick works if the magician k 阅读全文

摘要：In the year 3013, it has been 1000 years since the previous predicted rapture. However, the Maya will not play a joke any more and the Rapture finally 阅读全文