A1090. [COCI-2006_2007-contest6]#3 MARATON
编程题
普及/提高-
知识点
题目描述
Albert, Barbara, Casper, Dinko, Eustahije are starting a marathon game of tic-tac-toe, played on an N×N board.
Initially, all squares on the board are empty and players take turns writing the first letter of their name into any of the empty squares (because the players are elite, no two players have the same first letter).
The game ends when some player places 3 of his or her letters consecutively in a row, column or diagonally. That player is declared the winner.
Write a program that, given the state of the board, determines if the game is over and who won if it is.
Initially, all squares on the board are empty and players take turns writing the first letter of their name into any of the empty squares (because the players are elite, no two players have the same first letter).
The game ends when some player places 3 of his or her letters consecutively in a row, column or diagonally. That player is declared the winner.
Write a program that, given the state of the board, determines if the game is over and who won if it is.
输入格式
The first line of input contains the integer N (1 ≤ N ≤ 30), the size of the board.
The following N lines contain N characters each. The characters will be uppercase letters of the English alphabet or '.' (if the square is empty).
The input data will be such that there is at most one winner.
The following N lines contain N characters each. The characters will be uppercase letters of the English alphabet or '.' (if the square is empty).
The input data will be such that there is at most one winner.
输出格式
If the game is over, output the first letter of the winner's name. If not, output "ongoing" (even if the board is full).
输入输出样例
输入 #1
3 XOC XOC X..
输出 #1
X
输入 #2
4 .... ..A. AAB. .B.B
输出 #2
ongoing
输入 #3
3 ABB AAA BBA
输出 #3
A