View Compilation Error

0_0_30027533_29556.cpp: In function 'mat qp(mat, ll)':
0_0_30027533_29556.cpp:35:28: error: 'memset' was not declared in this scope
     memset(a.m,0,sizeof a.m);
                            ^
0_0_30027533_29556.cpp: In function 'int main()':
0_0_30027533_29556.cpp:64:25: error: 'stdin' was not declared in this scope
     freopen("i.txt","r",stdin);
                         ^
0_0_30027533_29556.cpp:64:30: error: 'freopen' was not declared in this scope
     freopen("i.txt","r",stdin);
                              ^
0_0_30027533_29556.cpp:66:18: error: 'scanf' was not declared in this scope
     scanf("%d",&T);
                  ^
0_0_30027533_29556.cpp:72:34: error: 'printf' was not declared in this scope
             printf("%lld\n",dt(n));
                                  ^
0_0_30027533_29556.cpp:75:39: error: 'memset' was not declared in this scope
         mat a; memset(a.m,0,sizeof a.m);
                                       ^
0_0_30027533_29556.cpp:94:44: error: 'printf' was not declared in this scope
         printf("%lld 474402220\n",qp(a,n-x));
                                            ^