View Compilation Error

0_0_14937104_12413.cpp: In function 'int main()':
0_0_14937104_12413.cpp:53:23: error: 'scanf' was not declared in this scope
   while (scanf("%d",&n)!=EOF)
                       ^
0_0_14937104_12413.cpp:53:26: error: 'EOF' was not declared in this scope
   while (scanf("%d",&n)!=EOF)
                          ^
0_0_14937104_12413.cpp:72:31: error: 'memset' was not declared in this scope
           memset(s,0,sizeof(s));
                               ^
0_0_14937104_12413.cpp:79:26: error: 'printf' was not declared in this scope
       printf("%lld\n",ans);
                          ^