CodeForces 3C Tic-tac-toe（模拟）

题意：XO游戏，现在给你一局游戏，让你判断是否合法，谁获胜，如果还没获胜，则输出下一步由谁走

思路：模拟..细节很多

#include<bits/stdc++.h>
using namespace std;
string s[3];

int check(char c)
{
for(int i=0;i<3;i++)
{
int win = 1;
for(int j=0;j<3;j++)
if(s[i][j]!=c)
win=0;
if(win==1)return win;
}
for(int i=0;i<3;i++)
{
int win=1;
for(int j=0;j<3;j++)
if(s[j][i]!=c)
win=0;
if(win==1)return win;
}
if(s[0][0]==c&&s[1][1]==c&&s[2][2]==c)return 1;
if(s[0][2]==c&&s[1][1]==c&&s[2][0]==c)return 1;
return 0;
}
int main()
{
for(int i=0;i<3;i++)
cin>>s[i];
int X=0,O=0;
for(int i=0;i<3;i++)
for(int j=0;j<3;j++)
if(s[i][j]=='X')X++;
else if(s[i][j]=='0')O++;
int Win1 = check('X');
int Win2 = check('0');
if(Win1&&Win2)return puts("illegal"),0;
if(Win1&&X-O!=1)return puts("illegal"),0;
if(Win2&&X!=O)return puts("illegal"),0;
if(X-O>1||O>X)return puts("illegal"),0;
if(Win1)return puts("the first player won"),0;
if(Win2)return puts("the second player won"),0;
if(X+O==9)return puts("draw"),0;
if(X==O)return puts("first"),0;
if(O==X-1)return puts("second"),0;

}

Description

Certainly, everyone is familiar with tic-tac-toe game. The rules are very simple indeed. Two players take turns marking the cells in a 3 × 3 grid (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.

You are given a 3 × 3 grid, each grid cell is empty, or occupied by a cross or a nought. You have to find the player (first or second), whose turn is next, or print one of the verdicts below:

illegal — if the given board layout can't appear during a valid game;
the first player won — if in the given board layout the first player has just won;
the second player won — if in the given board layout the second player has just won;
draw — if the given board layout has just let to a draw.

Input

The input consists of three lines, each of the lines contains characters ".", "X" or "0" (a period, a capital letter X, or a digit zero).

Output

Print one of the six verdicts: first, second, illegal, the first player won, the
second player won or draw.

Sample Input

Input

X0X
.0.
.X.

Output

second