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CSE390C Key to Final, Spring 2025 handout #9
1. Statement Output
------------------------------------------------------------
var1->f1(); foo 1
var2->f1(); foo 1
var3->f1(); bar 1
var4->f1(); baz 1
var5->f1(); mumble 1
var1->f2(); foo 2
var2->f2(); foo 2
var3->f2(); baz 2
var4->f2(); baz 2
var5->f2(); mumble 2
var1->f3(); baz 3
var2->f3(); mumble 3
var3->f3(); baz 3
var4->f3(); baz 3
var5->f3(); mumble 3
2. One possible solution appears below.
class int_list {
public:
int_list() {
// nothing to do
}
int_list(const int_list & rhs) {
for (int * p : rhs.values) {
values.push_back(new int(*p));
}
}
~int_list() {
for (int * p : values) {
delete p;
}
}
int_list & operator=(const int_list & rhs) {
if (this != &rhs) {
for (int * p : values) {
delete p;
}
values.clear();
for (int * p : rhs.values) {
values.push_back(new int(*p));
}
}
return *this;
}
int size() const {
return values.size();
}
int get(int index) const {
return *(values[index]);
}
void add(int value) {
values.push_back(new int(value));
}
private:
vector<int *> values;
};
3. One possible solution appears below.
class int_comparable {
public:
virtual int value() const = 0;
virtual ~int_comparable() { }
};
bool operator<(const int_comparable & lhs, const int_comparable & rhs) {
return lhs.value() < rhs.value();
}
class manhattan_point : public int_comparable {
public:
manhattan_point(int x = 0, int y = 0)
: x(x), y(y) {
// nothing else to do
}
int value() const {
return x + y;
}
private:
int x, y;
};
4. One possible solution appears below.
string acronym_for(const vector<string> & words) {
string result;
for (const string & s : words) {
result += toupper(s[0]);
}
return result;
}
5. One possible solution appears below.
int record_date(map<string, list<string>> & dates, const string & name1,
const string & name2) {
dates[name1].push_front(name2);
dates[name2].push_front(name1);
return count(dates[name1].begin(), dates[name1].end(), name2);
}
6. Two possible solutions appear below.
int random_pairwise_sorted(vector<int> data) {
random_shuffle(data.begin(), data.end());
int count = 0;
for (int i = 0; i < data.size() - 1; i++) {
if (data[i] <= data[i + 1]) {
count++;
}
}
return count;
}
int random_pairwise_sorted(vector<int> data) {
random_shuffle(data.begin(), data.end());
cout << "numbers = " << to_string(data) << endl;
int count = 0;
auto itr = data.begin();
while (itr + 1 != data.end()) {
if (is_sorted(itr, itr + 2)) {
count++;
}
itr++;
}
return count;
}
7. We expect to be able to chain together several assignment operations and
that would no longer compile, as in:
string s1 = "hello";
string s2, s3;
s2 = s3 = s1;
Because the return type of the assignment operator is a reference and not a
const reference, we would also expect to be able to write odd code like
this:
string s4 = "foo";
(s1 = s4)[0] = '#';
This would set s1 to "#oo" instead of "foo".
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