《Cracking the Coding Interview》——第17章：普通题——题目2

2014-04-28 22:05

题目：写个程序判断三连棋哪一方赢了。

解法：三个相同的棋子连成一条横线，竖线或者对角线就判断为赢了。

代码：

// 17.2 Write an algorithm to check if someone has won the tic-tac-toe game.
// Here is the game:
//    xo-
//    ox-
//    --x
// 'x' won the game.
// Rule: anyone who gets three consecutive pieces in a row, a column or a diagonal line first wins.
#include <cstdio>
using namespace std;

int check(int a[][3])
{
    if (a == nullptr) {
        return -1;
    }
    
    int i;
    for (i = 0; i < 3; ++i) {
        if (a[i][0] == a[i][1] && a[i][1] == a[i][2] && a[i][2] != 0) {
            return a[i][2];
        }
        if (a[0][i] == a[1][i] && a[1][i] == a[2][i] && a[2][i] != 0) {
            return a[i][2];
        }
    }
    if (a[0][0] == a[1][1] && a[1][1] == a[2][2] && a[2][2] != 0) {
        return a[2][2];
    }
    if (a[0][2] == a[1][1] && a[1][1] == a[2][0] && a[2][0] != 0) {
        return a[2][2];
    }
    
    return 0;
}

int main()
{
    int a[3][3];
    int i, j;
    
    for (i = 0; i < 3; ++i) {
        for (j = 0; j < 3; ++j) {
            scanf("%d", &a[i][j]);
        }
    }
    printf("%d\n", check(a));
    
    return 0;
}