Codeforces Round #369 (Div. 2) B. Chris and Magic Square 水题
B. Chris and Magic Square 题目连接: http://www.codeforces.com/contest/711/problem/B Description ZS the Coder and Chris the Baboon arrived at the entrance of Udayland. There is a n × n magic grid on the entrance which is filled with integers. Chris noticed that exactly one of the cells in the grid is empty, and to enter Udayland, they need to fill a positive integer into the empty cell. Chris tried filling in random numbers but it didn't work. ZS the Coder realizes that they need to fill in a positive integer such that the numbers in the grid form a magic square. This means that he has to fill in a