View Compilation Error

0_0_35334253_14776.cpp: In function 'void dijkstra(int)':
0_0_35334253_14776.cpp:17:28: error: 'memset' was not declared in this scope
  memset(vis, 0, sizeof(vis));//每次清空标记
                            ^
0_0_35334253_14776.cpp: In function 'int main()':
0_0_35334253_14776.cpp:62:30: error: 'memset' was not declared in this scope
   memset(rec, -1, sizeof(rec));
                              ^