View Compilation Error

0_0_34982062_9047.cpp: In function 'void bfs(int, int, int)':
0_0_34982062_9047.cpp:40:30: error: 'memset' was not declared in this scope
  memset(mark1,0,sizeof(mark1));         //清零
                              ^
0_0_34982062_9047.cpp: In function 'int main()':
0_0_34982062_9047.cpp:108:32: error: 'memset' was not declared in this scope
   memset(maze,'\0',sizeof(maze));
                                ^