View Compilation Error

0_0_35614052_23784.cpp: In function 'void dijk(int)':
0_0_35614052_23784.cpp:21:36: error: 'memset' was not declared in this scope
  memset(visit, false, sizeof(visit));
                                    ^
0_0_35614052_23784.cpp: In function 'int main()':
0_0_35614052_23784.cpp:44:33: error: 'memset' was not declared in this scope
   memset(graph, 0, sizeof(graph));
                                 ^