View Compilation Error

0_0_35152109_5798.cpp: In function 'void df(int)':
0_0_35152109_5798.cpp:55:38: error: 'memset' was not declared in this scope
             memset(c, 0x3f, sizeof(c));
                                      ^
0_0_35152109_5798.cpp: In function 'void solve()':
0_0_35152109_5798.cpp:77:27: error: 'memset' was not declared in this scope
     memset(d, 0, sizeof(d));
                           ^