View Compilation Error

0_0_17083388_20120.cpp: In member function 'void Hash_Set::init()':
0_0_17083388_20120.cpp:89:41: error: 'memset' was not declared in this scope
   tot = 0, memset(head, -1, sizeof(head));
                                         ^
0_0_17083388_20120.cpp: In member function 'void Astar::init()':
0_0_17083388_20120.cpp:108:30: error: 'memset' was not declared in this scope
   memset(vis, -1, sizeof(vis));
                              ^
0_0_17083388_20120.cpp: In member function 'void Astar::read()':
0_0_17083388_20120.cpp:112:21: error: 'strlen' was not declared in this scope
   int n = strlen(buf);
                     ^