Try C++ Institute : CPP valid & accurate questions and answers

What happens when you attempt to compile and run the following code?
#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
class A {
int a;
public:
A(int a) : a(a) {}
int getA() const { return a; } void setA(int a) { this?>a = a; }
bool operator==(const A & b) const { return a == b.a; }
};
bool compare(const A & a, const A & b) { return a == b; }
int main () {
int t[] = {1,2,3,3,5,1,2,4,4,5};
vector<A> v (t,t+10);
vector<A>::iterator it = v.begin();
while ( (it = adjacent_find (it, v.end(), compare)) != v.end()) {
cout<<it?v.begin()<<" ";it++;
}
cout<< endl;
return 0;
}

• A. program will run forever
• B. program outputs: 2 3
• C. program outputs: 2 7
• D. compilation error
• E. program outputs: 3 8

What happens when you attempt to compile and run the following code?
#include <iostream>
using namespace std;
template<class A>
void f(A a)
{
cout<<1<<endl;
}
void f(int a)
{
cout<<2<<endl;
}
int main()
{
int a = 1;
f<float>(a);
return 0;
}

• A. program displays: 2
• B. runtime exception
• C. program displays: 1
• D. compilation error

What will happen when you attempt to compile and run the following code?
# include <iostream>
# include <set>
#include <vector>
using namespace std;
int main(){
int t[] ={ 3, 4, 2, 1, 6, 5, 7, 9, 8, 0 };
vector<int>v(t, t+10);
set<int> s1(v.begin(),v.end());
s1.insert(v.begin(),v.end());
bool found = s1.find(7);
if (found){
cout<<"Element found!\n";
}else {
cout<<"Element not found!\n";
}
return 0;
}

• A. code will not compile
• B. program will display "Element found!"
• C. program will display "Element not found!\n"
• D. changing type of variable found to int will make this code compile

What will happen when you attempt to compile and run the code below, assuming that you enter the following sequence: 1 2 3 4 quit<enter>?
# include <iostream>
# include <string>
# include <list>
# include <algorithm>
using namespace std;
template<class T>struct Out {
ostream & out;
Out(ostream & o): out(o){}
void operator() (const T & val ) {out<<val<<" "; } };
int main ()
{
list<string> l;
while(cin.good())
{
string s;
cin>>s;
if (s == "quit") break;
l.push_back(s);
}
for_each(l.begin(), l.end(), Out<string>(cout));
return 0;
}
Program will output:

• A. 1 2 3 4 quit
• B. 1
• C. 1 2 3 4
• D. program runs forever without output

What happens when you attempt to compile and run the following code?
# include <iostream>
# include <string>
using namespace std;
template <class T>
class A {
T_v;
public:
A() {}
A(T v): _v(v){}
T getV() { return _v; }
void add(T & a) { _v+=a; }
void add(string & a) {
_v.insert(0, a);
}
};
int main()
{
A<string>a("Hello");
string s(" world!");
a.add(s);
cout << a.getV() <<endl;
return 0;
}

• A. program will run without any output
• B. program will display: Hello world!
• C. compilation error
• D. program will display: world!Hello