View Compilation Error

0_0_20722322_12160.cpp: In member function 'void samNode::clear()':
0_0_20722322_12160.cpp:8:52: error: 'memset' was not declared in this scope
  void clear(){ prv=0;val=0;memset(nxt,0,sizeof(nxt)); }
                                                    ^
0_0_20722322_12160.cpp: In function 'void extend(const int&)':
0_0_20722322_12160.cpp:40:39: error: 'memcpy' was not declared in this scope
    memcpy(y->nxt,x->nxt,sizeof(x->nxt));
                                       ^
0_0_20722322_12160.cpp: In function 'int main()':
0_0_20722322_12160.cpp:56:21: error: 'scanf' was not declared in this scope
  int T;scanf("%d",&T);
                     ^
0_0_20722322_12160.cpp:68:27: error: 'printf' was not declared in this scope
    printf("%d\n",ans[x][y]);
                           ^