View Compilation Error

0_0_22130017_20620.cpp: In member function 'void Suffix_Automation::init()':
0_0_22130017_20620.cpp:13:50: error: 'memset' was not declared in this scope
             memset(a[i].son, 0, sizeof (a[i].son));
                                                  ^
0_0_22130017_20620.cpp: In function 'int main()':
0_0_22130017_20620.cpp:62:32: error: 'strlen' was not declared in this scope
             len[i] = strlen(tmp);
                                ^
0_0_22130017_20620.cpp:66:35: error: 'memset' was not declared in this scope
         memset(vis, 0, sizeof(vis));
                                   ^