View Compilation Error

0_0_21156714_20992.cpp: In function 'int main()':
0_0_21156714_20992.cpp:24:37: error: 'memset' was not declared in this scope
         memset(visit,0,sizeof(visit));
                                     ^
0_0_21156714_20992.cpp:28:33: error: 'strcmp' was not declared in this scope
             if(strcmp(str,"STOP")==0)
                                 ^