View Compilation Error

0_0_37522678_3308.cpp: In function 'int bfs()':
0_0_37522678_3308.cpp:46:21: error: 'k' was not declared in this scope
                     k.x=xx;
                     ^
0_0_37522678_3308.cpp:58:29: error: 'k' was not declared in this scope
                             k.x=x;
                             ^
0_0_37522678_3308.cpp:83:29: error: 'k' was not declared in this scope
                             k.x=x;
                             ^
0_0_37522678_3308.cpp:92:29: error: 'k' was not declared in this scope
                             k.x=x;
                             ^