1 #include <bits/stdc++.h> 2 using namespace std; 3  4 const int maxn = 50 + 5; 5 char s[maxn][maxn]; 6 int n; 7 int dx[] = {0, 0, 1, 1}; 8 int dy[] = {1, 0, 0, -1}; 9 bool valid(int x, int y) {10     return x>=0&&y>=0&&x<n&&y<n;11 }12 int ety(int x, int y) {13     return x*n+y;14 }15 int vis[maxn*maxn];16 bool OK;17 int tx[] = {0, -1, -1, 0, 1, 1};18 int ty[] = {1, 1, 0, -1, -1, 0};19 void dfs(int v, int u, int deep) {20     if(vis[v]) {21         if((deep - vis[v])&1) OK = true;22         return ;23     }24     //printf("v : %d\n", v);25     bool repeat = false;26     //ans1 ++;27     vis[v] = deep;28     int x = v / n, y = v % n;29     for(int i=0; i<6; i++) {30         if(valid(x+tx[i], y+ty[i]) == false || s[x+tx[i]][y+ty[i]] != ‘X‘) continue;31         if(repeat == false && ety(x+tx[i], y+ty[i]) == u) {32             repeat = true; continue;33         }34         dfs(ety(x+tx[i], y+ty[i]), v, deep+1);35     }36 }37 int main() {38     freopen("in.txt", "r", stdin);39     freopen("out.txt", "w", stdout);40     int T;41     scanf("%d", &T);42     while(T--) {43         memset(vis, 0, sizeof(vis));44         scanf("%d", &n);45         getchar();46         int ans = 0;47         for(int i=0; i<n; i++) {48             gets(s[i]);49         }50         OK = false;51         for(int i=0; i<n; i++) {52             for(int j=0; j<n; j++) {53                 if(vis[ety(i, j)] == 0 && s[i][j] == ‘X‘) dfs(ety(i, j), -1, 1);54                 int t = 0;55                 for(int k=0; k<3; k++) {56                     if(valid(i+dx[k], j+dy[k]) && s[i+dx[k]][j+dy[k]] == ‘X‘) t ++;57                 }58                 ans = max(ans, t);59                 t = 0;60                 for(int k=1; k<4; k++) {61                     if(valid(i+dx[k], j+dy[k]) && s[i+dx[k]][j+dy[k]] == ‘X‘) t ++;62                 }63                 ans = max(ans, t);64             }65         }66         if(ans != 2) printf("%d\n", ans);67         else {68             printf("%d\n", ans+OK);69         }70     }71     return 0;72 }