CPP Online Practice Questions and Answers

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

#include

#include

#include

using namespace std;

int main () {

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

vector v (t,t+15);

vector::iterator it = search_n(v.begin(), v.end(), 4, 2);

cout<< it?v.begin()<

return 0;

}

Program outputs:

A. 10

B. 3

C. 1

D. 15

E. compilation error

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

#include

#include

#include

using namespace std;

templatestruct Out {

ostream and out;

Out(ostream and o): out(o){}

void operator() (const T and val ) { out<

int main() {

int t1[]={3,2,4,1,5};

int t2[]={6,10,8,7,9};

vector v1(10);

sort(t1, t1+5); sort(t2, t2+5);

copy(t1,t1+5,v1.begin());

copy(t2,t2+5,v1.begin()+5);

merge(v1.begin(), v1.begin()+5,v1.end());

for_each(v1.begin(), v1.end(), Out(cout));cout<

return 0;

}

Program outputs:

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

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

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

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

E. compilation error

Which changes introduced independently will allow the code to compile and display "one" "eight" "nine" "ten"? Choose all that apply.

#include

#include

#include

using namespace std;

class A {

int a;

public:

A(int a):a(a){}

int getA() const { return a;}

/* Insert Code Here 1 */

};

/* Insert Code Here 2 */

int main(){

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

string s[] = {"three", "four", "two", "one", "six","five", "seven", "nine","eight","ten"};

multimap m;/* Replace Code Here 3 */

for(int i=0; i<10; i++) {

m.insert(pair(A(t[i]),s[i]));

}

m.erase(m.lower_bound(2),m.upper_bound(7));

multimap::iterator i=m.begin();/* Replace Code Here 4 */

for( ; i!= m.end(); i++) {

cout<second<<" ";

}

cout<

return 0;

}

A. operator int() const { return a;} inserted at Place 1

B. bool operator < (const A and b) const { return a

C. bool operator < (const A and b) const { return b.a

D. struct R { bool operator ()(const A and a, const A and b) { return a.getA() m; replacong line marked 4 with multimap::iterator i=m.begin();

Which lines of the code below contain proper instantiation of queue objects?

#include

#include

#include

#include

#include

using namespace std;

int main()

{

deque mydeck;

list mylist;

vector myvector;

queue first; // line I

queue second(mydeck);// line II

queue third(second);// line III

queue fourth(mylist);// line IV

queue fifth(myvector);// 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;

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

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

#include

#include

#include

#include

using namespace std;

class B { int val;

public:

B(int v=0):val(v){}

int getV() const {return val;}

B operator ?(const B andb )const { return B(val ? b.val);}}; ostream and operator <<(ostream and out, const B and v) { out<

templatestruct Out {

ostream and out;

Out(ostream and o): out(o){}

void operator() (const T and val ) { out<

int main() {

B t1[]={1,2,3,4,5,6,7,8,9,10};

B t2[]={1,2,3,4,5,6,7,8,9,10};

vector v1(t1, t1+10);

vector v2(t2, t2+10);

vector v3(10);

transform(v1.begin(), v1.end(), v2.rbegin(), v3.begin(), minus());

for_each(v3.rbegin(), v3.rend(), Out(cout));cout<

return 0;

}

Program outputs:

A. 9 7 5 3 1 ?1 ?3 ?5 ?7 ?9

B. ?1 ?3 ?5 ?7 ?9 9 7 5 3 1

C. 1 3 5 7 9 ?1 ?3 ?5 ?7 ?9

D. 1 3 5 7 9 ?1 ?3 ?5 ?7 ?9

E. ?9 ?7 ?5 ?3 ?1 1 3 5 7 9