FOJ Problem 2283 Tic-Tac-Toe（暴力枚举）——第八届福建省大学生程序设计竞赛-重现赛

传送门
Kim likes to play Tic-Tac-Toe.

Given a current state, and now Kim is going to take his next move. Please tell Kim if he can win the game in next 2 moves if both player are clever enough.

Here “next 2 moves” means Kim’s 2 move. (Kim move,opponent move, Kim move, stop).

Game rules:

Tic-tac-toe (also known as noughts and crosses or Xs and Os) is a paper-and-pencil game for two players, X and O, who take turns marking the spaces in a 3×3 grid. The player who succeeds in placing three of their marks in a horizontal, vertical, or diagonal row wins the game.

Input

First line contains an integer T (1 ≤ T ≤ 10), represents there are T test cases.

For each test case: Each test case contains three lines, each line three string(“o” or “x” or “.”)(All lower case letters.)

x means here is a x

o means here is a o

. means here is a blank place.

Next line a string (“o” or “x”) means Kim is (“o” or “x”) and he is going to take his next move.

Output

For each test case:

If Kim can win in 2 steps, output “Kim win!”

Otherwise output “Cannot win!”

题目大意：

有两个人要玩游戏，游戏规则如下：
一个人用 X , 另一个人用 O， 如果一个人有一行或者一列或者对角线都是相同元素，那么这个人就胜出了，现在给定一个状态，让你求在这个状态下，你在走两步，能不能赢（俩个人都是采用的最优策略）

解题思路：
暴力枚举。首先枚举一遍，观察能不能只走一步就胜出。如果能胜出，那么直接输出结果；否则就在枚举把当前为 . 的换成需要替换的元素，枚举另一个人的最优选择，如果没有最优选择随机一个为 . 的元素，然后在进行判断就OK了，就是代码稍微麻烦了一点，不过还是很好想的。

代码：

#include <iostream>#include <stdio.h>#include <stdlib.h>#include <math.h>#include <algorithm>using namespace std;const int MAXN = 10;char g[MAXN][MAXN];int check(char ch){    if(g[0][0]==ch && g[1][1]==ch && g[2][2]==ch) return 1;    if(g[0][3]==ch && g[1][1]==ch && g[3][0]==ch) return 1;    if(g[0][0]==ch && g[0][1]==ch && g[0][2]==ch) return 1;    if(g[1][0]==ch && g[1][1]==ch && g[1][2]==ch) return 1;    if(g[2][0]==ch && g[2][1]==ch && g[2][2]==ch) return 1;    if(g[0][0]==ch && g[1][0]==ch && g[2][0]==ch) return 1;    if(g[0][1]==ch && g[1][1]==ch && g[2][1]==ch) return 1;    if(g[0][2]==ch && g[1][2]==ch && g[2][2]==ch) return 1;    return 0;}int main(){    int T; scanf("%d", &T);    while(T--){        char ch;        for(int i=0; i<3; i++) for(int j=0; j<3; j++) cin>>ch, g[i][j] = ch;        cin>>ch;        int ok = 0;        for(int i=0; i<3; i++){            for(int j=0; j<3; j++){                if(g[i][j] == '.'){                    g[i][j] = ch;                    if(check(ch)){                        ok = 1;                        goto A;                    }                    g[i][j] = '.';                }            }        }A:;        if(ok) puts("Kim win!");        else {            ok = 0;            for(int i=0; i<3; i++){               for(int j=0; j<3; j++){                   if(g[i][j] == '.'){                        g[i][j] = ch;                        int ta = -1, tb = -1;                        for(int ii=0; ii<3; ii++){                            for(int jj=0; jj<3; jj++){                                if(g[ii][jj] == '.'){                                    g[ii][jj] = ch;                                    if(check(ch)){                                        ta = ii, tb = jj;                                        goto B;                                    }                                    g[ii][jj] = '.';                                }                            }                        }                        for(int ii=0; ii<3; ii++){                            for(int jj=0; jj<3; jj++){                                if(g[ii][jj] == '.'){                                    ta = ii, tb = jj;                                    goto B;                                }                            }                        }B:;                        if(ch == 'o') g[ta][tb] = 'x';                        else if(ch == 'x') g[ta][tb] = 'o';                        for(int iii=0; iii<3; iii++){                            for(int jjj=0; jjj<3; jjj++){                                if(g[iii][jjj] == '.'){                                    g[iii][jjj] = ch;                                    if(check(ch)){                                        ok = 1;                                        goto C;                                    }                                    g[iii][jjj] = '.';                                }                            }                        }                        g[ta][tb] = '.';                        g[i][j] = '.';                   }               }            }            C:;            if(ok) puts("Kim win!");            else puts("Cannot win!");        }    }    return 0;}/**                   _ooOoo_                  o8888888o                  88" . "88                  (| -_- |)                  O\  =  /O               ____/`---'\____             .'  \\|     |//  `.            /  \\|||  :  |||//  \           /  _||||| -:- |||||-  \           |   | \\\  -  /// |   |           | \_|  ''\---/''  |   |           \  .-\__  `-`  ___/-. /         ___`. .'  /--.--\  `. . __      ."" '<  `.___\_<|>_/___.'  >'"".     | | :  `- \`.;`\ _ /`;.`/ - ` : | |     \  \ `-.   \_ __\ /__ _/   .-` /  /======`-.____`-.___\_____/___.-`____.-'======                   `=---='^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^         佛祖保佑       每次AC**/