View Compilation Error

0_0_7904121_14506.cpp: In function `int bfs()':
0_0_7904121_14506.cpp:77: error: `vis' undeclared (first use this function)
0_0_7904121_14506.cpp:77: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_7904121_14506.cpp: In function `int main()':
0_0_7904121_14506.cpp:107: error: `vis' undeclared (first use this function)