View Compilation Error

0_0_17298398_21190.cpp: In function 'void reader()':
0_0_17298398_21190.cpp:9:39: error: 'memset' was not declared in this scope
       memset(edge, true, sizeof (edge));
                                       ^
0_0_17298398_21190.cpp: In function 'bool init_prev()':
0_0_17298398_21190.cpp:39:39: error: 'memset' was not declared in this scope
       memset(linkp, -1, sizeof (linkp));
                                       ^
0_0_17298398_21190.cpp: In function 'bool min_prev(int)':
0_0_17298398_21190.cpp:59:61: error: 'memset' was not declared in this scope
                         memset(vis, 0, sizeof (vis[0]) * pos);
                                                             ^
0_0_17298398_21190.cpp: In function 'bool next_prev(int)':
0_0_17298398_21190.cpp:75:39: error: 'memset' was not declared in this scope
       memset(used, true, sizeof (used));
                                       ^
0_0_17298398_21190.cpp: In function 'bool work()':
0_0_17298398_21190.cpp:103:36: error: 'memset' was not declared in this scope
       memset(used, 0, sizeof (used));
                                    ^