摘要： A robot has to patrol around a rectangular area which is in a form of m x n grid (m rows and ncolumns). The rows are labeled from 1 to m. The columns 阅读全文

摘要： Little Valentine liked playing with binary trees very much. Her favorite game was constructing randomly looking binary trees with capital letters in t 阅读全文

摘要： Some of the secret doors contain a very interesting word puzzle. The team of archaeologists has to solve it to open that doors. Because there is no ot 阅读全文