View Compilation Error

0_0_16827645_11258.cpp: In function 'void init()':
0_0_16827645_11258.cpp:29:34: error: 'memset' was not declared in this scope
     memset(head, -1, sizeof(head));
                                  ^
0_0_16827645_11258.cpp: In function 'int dij(int, int)':
0_0_16827645_11258.cpp:46:33: error: 'memset' was not declared in this scope
     memset(done, 0, sizeof(done));
                                 ^