View Compilation Error

0_0_23037974_13404.cpp: In function 'void BFS()':
0_0_23037974_13404.cpp:34:24: error: 'memset' was not declared in this scope
  memset(hs,0,sizeof(hs));
                        ^
0_0_23037974_13404.cpp: In function 'int main()':
0_0_23037974_13404.cpp:155:30: error: 'memset' was not declared in this scope
   memset(Step,-1,sizeof(Step));
                              ^