Free C++ Institute CPP Questions

What happens when you attempt to compile and run the following code? #include <vector> #include <iostream> #include <algorithm> using namespace std; template<class T>struct Out { ostream & out; Out(ostream & o): out(o){} void operator()(const T & val ) { out<<val<<" "; } }; struct Sequence { int start; Sequence(int start):start(start){} int operator()() { return start++ ; }}; int main() { vector<int> v1(10); generate(v1.rbegin(), v1.rend(), Sequence(1)); rotate(v1.begin(),v1.begin() + 1, v1.end() ); for_each(v1.begin(), v1.end(), Out<int>(cout) );cout<<endl; return 0; } Program outputs:

What happens when you attempt to compile and run the following code? #include <iostream> #include <fstream> #include <string> #include <list> #include <algorithm> #include <iomanip> using namespace std; class B { int val; public: B(int v=0):val(v){} int getV() const {return val;} operator int() const { return val; };}; template<class T>struct Out { ostream & out; Out(ostream & o): out(o){} void operator() (const T & val ) {out<<setw(3)<<hex<<val; } }; int main () { int t[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}; fstream f("test.out", ios::trunc|ios::out); list<B> l(t, t+10); for_each(l.begin(), l.end(), Out<B>(f)); f.close(); f.open("test.out"); for( ; f.good() ; ) { B i; f>>i; cout<<i<<" "; } f.close(); return 0; }

What will happen when you attempt to compile and run the code below, assuming that you enter the following sequence: one two three<enter>? #include <iostream> #include <string> using namespace std; int main () { string a; cin>>a; cout<<a<<endl; return 0; } Program will output:

What will happen when you attempt to compile and run the following code? #include <iostream> #include <map> #include <vector> #include <sstream> #include <string> using namespace std; int main() { int t[] = { 3, 4, 2, 1, 0, 3, 4, 1, 2, 0 }; vector<int> v(t, t + 10); multimap<int, string> m; for (vector<int>::iterator i = v.begin(); i != v.end(); i++) { stringstream s;s << *i << *i; m.insert(pair<int, string>(*i, s.str())); } pair<multimap<int, string>::iterator, multimap<int, string>::iterator> range; range = m.equal_range(2); for (multimap<int, string>::iterator i = range.first; i != range.second; i++) { cout << i?>first << " "; } return 0; } The output will be:

What happens when you attempt to compile and run the following code? #include <vector> #include <iostream> #include <algorithm> using namespace std; class B { int val; public: B(int v):val(v){} int getV() const {return val;} bool operator < (const B & v) const { return val>v.val;} }; ostream & operator <<(ostream & out, const B & v) { out<<v.getV(); return out;} template<class T>struct Out { ostream & out; Out(ostream & o): out(o){} void operator() (const T & val ) { out<<val<<" "; } }; int main() { B t1[]={3,2,4,1,5}; B t2[]={5,6,8,2,1}; vector<B> v1(10,0); sort(t1, t1+5); sort(t2, t2+5); set_intersection(t1,t1+5,t2,t2+5,v1.begin()); for_each(v1.begin(), v1.end(), Out<B>(cout));cout<<endl; return 0; } Program outputs: