View Compilation Error

0_0_24459998_23579.cpp: In function 'bool bfs()':
0_0_24459998_23579.cpp:32:29: error: 'memset' was not declared in this scope
     memset(dis,0,sizeof(dis));
                             ^
0_0_24459998_23579.cpp: In function 'int main()':
0_0_24459998_23579.cpp:93:36: error: 'memset' was not declared in this scope
         memset(head,-1,sizeof(head));
                                    ^