poj3194

简单题， BFS

#include <iostream>
#include <cstdlib>
#include <cstring>
#include <cstdio>
using namespace std;

#define maxn 105

struct Point
{
    int x, y;
    Point()
    {
    }
    Point(int xx, int yy): x(xx), y(yy)
    {
    }
}q[maxn * maxn];

int n;
int map[maxn][maxn];
bool vis[maxn][maxn];
int dir[4][2] = {{1, 0},{0, 1},{-1, 0},{0, -1}};

void input()
{
    memset(map, 0, sizeof(map));
    for (int i = 1; i < n; i++)
        for (int j = 0; j < n; j++)
        {
            int a, b;
            scanf("%d%d", &a, &b);
            a--;
            b--;
            map[a][b] = i;
        }
}

int bfs(Point s)
{
    int front, rear;
    front = rear = 0;
    q[rear++] = s;
    vis[s.x][s.y] = true;
    int ret = 1;
    while (front != rear)
    {
        Point p = q[front++];
        for (int i = 0; i < 4; i++)
        {
            Point a(p.x + dir[i][0], p.y + dir[i][1]);
            if (a.x >= 0 && a.y >= 0 && a.x < n && a.y < n && !vis[a.x][a.y] && map[a.x][a.y] == map[p.x][p.y])
            {
                vis[a.x][a.y] = true;
                q[rear++] = a;
                ret++;
            }
        }
    }
    return ret;
}

bool work()
{
    memset(vis, 0, sizeof(vis));
    for (int i = 0; i < n; i++)
        for (int j = 0; j < n; j++)
            if (!vis[i][j])
            {
                int x = bfs(Point(i, j));
                if (x != n)
                    return false;
            }
    return true;
}

int main()
{
    //freopen("t.txt", "r", stdin);
    while (scanf("%d", &n), n)
    {
        input();
        if (work())
            printf("good\n");
        else
            printf("wrong\n");
    }
    return 0;
}