C++ Institute CPP 問題集

質問 1：
What happens 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, 6, 5, 7, 9, 8, 0 };
vector<int> v(t, t+10);
map<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()));
}
for(map<int, string>::iterator i=m.begin();i!= m.end(); i++) {
cout<<*i<<" ";
}
return 0;
}
A. program outputs: 00 11 22 33 44 55 66 77 88 99
B. compilation error
C. program outputs: 0 1 2 3 4 5 6 7 8 9
D. program outputs: 0 00 1 11 2 22 3 33 4 44 5 55 6 66 7 77 8 88 9 99
E. program outputs: 3 4 2 1 6 5 7 9 8 0
正解：B

質問 2：
What happens when you attempt to compile and run the following code?
# include <deque>
# include <list>
# include <iostream>
using namespace std;
int main ()
{
list<int>l1;
deque<int>d1;
for(int i=0; i<5; i++)
{
l1.push_back(i);l1.push_front(i);
d1.push_back(i);d1.push_front(i);
}
for(int i=0; i<d1.size(); i++)
{
cout<<d1[i]<<" "<<l1[i]<<" ";
}
cout<<endl;
return 0;
}
A. compilation error due to line 16
B. program displays 4 4 3 3 2 2 1 1 0 0 0 0 1 1 2 2 3 3 4 4
C. compilation error due to line 11
D. compilation error due to line 12
E. runtime exception
正解：A

質問 3：
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.getline(a);
cout<<a<<endl;
return 0;
}
Program will output:
A. compilation error
B. one two three
C. the result is unspecified
D. runtime exception
E. one
正解：A

質問 4：
What happens when you attempt to compile and run the following code?
#include <list>
#include <iostream>
using namespace std;
template<class T>
void print(T start, T end) {
while (start != end) {
std::cout << *start << " "; start++;
}
}
int main()
{
int t1[] ={ 1, 7, 8, 4, 5 };
list<int> l1(t1, t1 + 5);
int t2[] ={ 3, 2, 6, 9, 0 };
list<int> l2(t2, t2 + 5);
l1.sort();
list<int>::iterator it = l2.begin();
it++; it++;
l1.splice(l1.end(),l2, it, l2.end());
print(l1.begin(), l1.end()); cout<<"Size:"<<l1.size()<<" ";
print(l2.begin(), l2.end()); cout<<"Size:"<<l2.size()<<endl;
return 0;
}
A. program outputs: 1 4 5 7 8 6 9 0 Size:8 3 2 6 9 0 Size:5
B. program outputs: 0 1 4 5 6 7 8 9 Size:8 3 2 6 9 0 Size:5
C. program outputs: 0 1 4 5 6 7 8 9 Size:8 3 2 Size:2
D. compilation error
E. program outputs: 1 4 5 7 8 6 9 0 Size:8 3 2 Size:2
正解：E

質問 5：
What will happen when you attempt to compile and run the code below, assuming that you enter the following sequence: 1 2 3<enter>?
# include <iostream>
# include <string>
# include <sstream>
using namespace std;
int main ()
{
string s;
getline(cin, s);
stringstream input(s);
stringstream output;
for( ; !input.fail() ; )
{
int i;
input>>i;
output<<hex<<i<<" ";
}
cout<<output.str();
return 0;
}
Program will output:
A. 0x1 0x2 0x3
B. 1 2 3 3
C. program runs forever without output
D. 1 2 3
E. 0x1 0x2 0x3 0x3
正解：B

質問 6：
What happens when you attempt to compile and run the following code?
# include <iostream>
# include <map>
using namespace std;
int main() {
int t[] = { 1, 1, 2, 2, 3, 3, 4, 4, 5, 5 };
string s[] = { "one", "one", "two", "two", "three","three", "four", "four", "five", "five"}; multimap<int, string> m;
for (int i = 0; i < 10; i++) {
m.insert(pair<int, string>(t[i], s[i]));
}
if (m.count(3) == 2) {
m.erase(3);
}
for (multimap<int, string>::iterator i = m.begin(); i != m.end(); i++) { cout << i?>first << " ";
}
return 0;
}
A. program outputs: one two three four five
B. program outputs: 1 2 3 4 5
C. program outputs: 1 1 2 2 4 4 5 5
D. program outputs: 1 1 2 2 3 4 4 5 5
E. program outputs: 1 2 4 5
正解：C