View Compilation Error

0_0_14271103_19912.cpp: In function 'void bfs(int, int)':
0_0_14271103_19912.cpp:27:31: error: 'memset' was not declared in this scope
     memset(vis, 0, sizeof(vis));
                               ^
0_0_14271103_19912.cpp: In function 'int main()':
0_0_14271103_19912.cpp:88:45: error: 'memset' was not declared in this scope
             memset(graph, '1', sizeof(graph));
                                             ^