CPP Online Practice Questions and Answers

What will happen when you attempt to compile and run the following code?

#include

#include

#include

using namespace std;

int main(){

int t[] ={ 3, 4, 2, 1, 6, 5, 7, 9, 8, 0 };

vectorv(t, t+10);

set 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. program will display "Element found!"

B. program will display "Element not found!\n"

C. code will not compile

D. changing type of variable found to int will make this code compile

Which pieces of code inserted independently into places marked 1 and 2 will cause the program to compile and display: 0 1 2 3 4 5 6 7 8 9? Choose all that apply.

#include

#include

using namespace std;

class A { int a; public:

A(int a){ this?>a=a;}

//insert code here 1

};

//insert code here 2

template void print(T start, T end) {

while (start != end) {

std::cout << *start << " "; start++;

}

}

int main() {

A t1[] ={ 1, 7, 8, 4, 5 };list l1(t1, t1 + 5);

A t2[] ={ 3, 2, 6, 9, 0 };list l2(t2, t2 + 5);

l1.sort();l2.sort();l1.merge(l2);

print(l1.begin(), l1.end());

print(l2.begin(), l2.end()); cout<

return 0;

}

A. place 1: operator int() { return a; }

B. place 1: operator int() { return a; } bool operator < (const A and b) { return this?>a< b.a;}

C. place 1: bool operator < (const A and b) { return this?>a< b.a;}

D. place 1: bool operator < (const A and b) { return this?>a< b.a;} friend ostream and operator <<(ostream and c, const A and a); place 2: ostream and operator <<(ostream and c, const A and a) { c<

E. place 1: bool operator < (const A and b) { return this?>a< b.a;} place 2: ostream and operator <<(ostream and c, const A and a) { c<

What happens when you attempt to compile and run the following code?

#include

#include

using namespace std;

template

class A {

T_v;

public:

A() {}

A(T v): _v(v){}

T getV() { return _v; }

void add(T and a) { _v+=a; }

void add(string and a) {

_v.insert(0, a);

}

};

int main()

{

Aa("Hello");

string s(" world!");

a.add(s);

cout << a.getV() <

return 0;

}

A. program will display: Hello world!

B. compilation error

C. program will display: world!Hello

D. program will run without any output

What happens when you attempt to compile and run the following code?

#include

#include

#include

using namespace std;

void print(int v) {

cout<

}

struct Sequence {

int start;

Sequence(int start):start(start){}

int operator()() {

return start++;

}

};

int main() {

vector v1(10);

generate_n(v1.begin(), 10, Sequence(1));

for_each(v1.begin(), v1.end(), print);

cout<

return 0;

}

Program outputs:

A. 1 2 3 4 5 6 7 8 9 10

B. 0 0 0 0 0 0 0 0 0 0

C. compilation error

D. no output

Which are NOT valid instantiations of priority_queue object:

#include

#include

#include

#include

#include

using namespace std;

int main()

{

deque mydeck;list mylist; vector myvector;

priority_queue first;//line I

priority_queue > second;//line II

priority_queue third(first);//line III

priority_queue > fourth(third);//line IV

priority_queue > fifth(myvector.begin(), myvector.end());//line V

return 0;

}

A. line I

B. line II

C. line III

D. line IV

E. line V

What happens when you attempt to compile and run the following code? #include

#include

#include

using namespace std;

int main ()

{

int t[] = {1, 2 ,3 ,4 ,5};

vectorv1(t, t+5);

dequed1;

d1.assign(v1.end(), v1.begin());

for(int i=0; i

{

cout<

}

cout<

return 0;

}

A. program outputs 5 4 3 2 1

B. program outputs 1 2 3 4 5

C. compilation error in line 8

D. compilation error in line 10

E. segmentation fault runtime exception

What happens when you attempt to compile and run the following code?

#include

#include

#include

using namespace std;

int main ()

{

int t[] = {1, 2 ,3 ,4 ,5, 6 , 7, 8 , 9, 10};

vectorv1(t, t+10);

dequed1(t, t+10);

d1.empty();

v1.empty();

if (v1.isempty())

{

cout<<"I am empty ";

}

else

{

cout<<"I am not empty ";

}

cout<

return 0;

}

A. program outputs: I am empty 0 0

B. program outputs: I am not empty 0 0

C. compilation error

D. program outputs: I am not empty 10 10