View Compilation Error

0_0_37860517_4296.cpp: In function 'void dfs(int, int)':
0_0_37860517_4296.cpp:17:8: error: 'vis' was not declared in this scope
     if(vis[xt][yt]==1){ //剪枝 能走到终点即退出 
        ^
0_0_37860517_4296.cpp:26:13: error: 'vis' was not declared in this scope
             vis[xt][yt]=1;
             ^
0_0_37860517_4296.cpp: In function 'int main()':
0_0_37860517_4296.cpp:99:13: error: 'vis' was not declared in this scope
             vis[xt][yt]=0;
             ^