Clicker Questions - 04-More-Strings
(BTW, I'm omitting the "include" and "using" lines to conserve space. Just pretend that the correct ones are there.)
input-1.txt
Dear Earl,
Great Job!
Love Madison
p1.cpp
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int main()
{
string s, r;
while (cin >> s) {
r += s;
}
cout << r.size() << endl;
return 0;
}
- Question 1: What is the output of p1.cpp when it runs with input-1.txt as standard input?
Answer
The program reads six strings:
- "Dear" -- 4 characters.
- "Earl," -- 5 characters (the comma counts).
- "Great" -- 5 characters
- "Job!" -- 4 characters (the exclamation point counts).
- "Love" -- 4 characters
- "Madison" -- 7 characters
Thus, r will be the sum of the characters. The answer is 29.
p2.cpp
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int main()
{
string s;
vector <string> v;
size_t i;
int total;
while (cin >> s) v.push_back(s);
total = 0;
for (i = 1; i < v.size(); i++) {
total += (v[i][0] - v[i-1][0]);
}
cout << total << endl;
return 0;
}
- Question 2: What is the output of p2.cpp when it runs with input-1.txt as standard input?
Answer
The program reads six strings:
This reads in the same six strings. It then sums up the difference between each adjacent pair of first characters:
- ('E' - 'D') = 1.
- ('G' - 'E') = 2.
- ('J' - 'G') = 3.
- ('L' - 'J') = 2.
- ('M' - 'L') = 1.
The sum is 9.
input-2.txt
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seven
3
p3.cpp
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int main()
{
int i;
int total;
total = 0;
while (!cin.fail()) {
cin >> i;
total++;
}
cout << total << endl;
return 0;
}
- Question 3: What is the output of p3.cpp when it runs with input-2.txt as standard input?
Answer
Does this question seem familiar? It should -- it's pretty much the same as the eof() question from the last set. cin.fail() doesn't return true until you try to read "seven". Thus, that while loop is exectued four times -- the answer is 4.