View Compilation Error

0_0_21968032_1240.cpp: In function 'bool solve()':
0_0_21968032_1240.cpp:47:28: error: 'memset' was not declared in this scope
     memset(in, 0, sizeof in);
                            ^
0_0_21968032_1240.cpp: In function 'int main()':
0_0_21968032_1240.cpp:98:34: error: 'memset' was not declared in this scope
         memset(vis, 0, sizeof vis);
                                  ^