Codeforces Beta Round #3 / 3C Tic-tac-toe (超级模拟)

C. Tic-tac-toe

http://codeforces.com/problemset/problem/3/C

time limit per test

memory limit per test

input

output

3 × 3grid (one player always draws crosses, the other — noughts). The player who succeeds first in placing three of his marks in a horizontal, vertical or diagonal line wins, and the game is finished. The player who draws crosses goes first. If the grid is filled, but neither Xs, nor 0s form the required line, a draw is announced.

3 × 3

• illegal
• the first player won
• the second player won
• draw

Input

.", "X" or "0" (a period, a capital letter X, or a digit zero).

Output

first, second, illegal, the first player won, the second player won or draw.

Sample test(s)

input

X0X .0. .X.

output

second

一道我WA了n遍的题目（可能是晚上状态不好）

完整代码：

/*30ms,0KB*/

#include<cstdio>

char grid[3][3];

int main(void)
{
	int fcount = 0, scount = 0;
	bool fwin = false, swin = false; ///局部变量一定要赋值后才能用
	for (int i = 0; i < 3; ++i)
	{
		for (int j = 0; j < 3; j++)
		{
			grid[i][j] = getchar();
			if (grid[i][j] == 'X')
				++fcount;
			else if (grid[i][j] == '0')
				++scount;
		}
		getchar();
	}
	if (fcount - scount > 1 || fcount - scount < 0) ///永远是X(first)先走
		printf("illegal");
	else
	{
		///行
		for (int i = 0; i < 3; ++i)
		{
			if (grid[i][0] == grid[i][1] && grid[i][0] == grid[i][2] && grid[i][0] != '.')
			{
				if (grid[i][0] == 'X')
					fwin = true;
				else
					swin = true;
			}
		}
		if (fwin && swin)
		{
			printf("illegal");
			return 0;
		}
		else if (fwin || swin)
		{
			if (fwin && fcount == scount || swin && fcount > scount)
			{
				printf("illegal");
				return 0;
			}
			printf(fwin ? "the first player won" : "the second player won");
			return 0;
		}
		///列
		for (int i = 0; i < 3; ++i)
		{
			if (grid[0][i] == grid[1][i] && grid[0][i] == grid[2][i] && grid[0][i] != '.')
			{
				if (grid[0][i] == 'X')
					fwin = true;
				else
					swin = true;
			}
		}
		if (fwin && swin)
		{
			printf("illegal");
			return 0;
		}
		else if (fwin || swin)
		{
			if (fwin && fcount == scount || swin && fcount > scount)
			{
				printf("illegal");
				return 0;
			}
			printf(fwin ? "the first player won" : "the second player won");
			return 0;
		}
		///斜
		if (grid[1][1] != '.' && (grid[0][0] == grid[1][1] && grid[2][2] == grid[1][1] || grid[0][2] == grid[1][1] && grid[2][0] == grid[1][1]))
		{
			if (grid[1][1] == 'X')
				fwin = true;
			else
				swin = true;
		}
		if (fwin || swin)
		{
			if (fwin && fcount == scount || swin && fcount > scount)
			{
				printf("illegal");
				return 0;
			}
			printf(fwin ? "the first player won" : "the second player won");
			return 0;
		}
		printf(fcount + scount == 9 ? "draw" : fcount > scount ? "second" : "first");
	}
	return 0;
}