View Compilation Error

0_0_19820018_18905.cpp: In function 'void init()':
0_0_19820018_18905.cpp:19:44: error: 'memset' was not declared in this scope
      memset(visited, false, sizeof(visited));
                                            ^
0_0_19820018_18905.cpp: In function 'bool bfs(int)':
0_0_19820018_18905.cpp:32:44: error: 'memset' was not declared in this scope
      memset(visited, false, sizeof(visited));
                                            ^
0_0_19820018_18905.cpp: In function 'int main()':
0_0_19820018_18905.cpp:60:35: error: 'memset' was not declared in this scope
           memset(in, 0, sizeof(in));
                                   ^
0_0_19820018_18905.cpp:64:45: error: 'strlen' was not declared in this scope
                 addedge(a[0]-'a', a[strlen(a)-1]-'a');
                                             ^