cpp/references/reverse

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Description
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Write a function that reverses a vector that is passed in by reference.
E.g., if <tt>vec</tt> contains 2, 0, 1, 5 in that order, after calling
<tt>reverse(vec)</tt>, it should contain 5, 1, 0, 2 in that order.
<br>
Call the <tt>swap</tt> function defined previously to help you.

Epilogue
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shown when solved

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Remarks
Comments, history, license, etc.

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Engine
Choices
json list of string, bool pairs
e.g. [["good", true], ["bad", false]]

Correct answer
Template / Reference solution

Template / Reference solution

#include <iostream>
#include <vector>
using namespace std;

// assume this is defined for you
void swap(int& a, int& b)\fake[;]\
\hide[
{
int tmp = a;
a = b;
b = tmp;
}
]\
// for testing: print contents of vector
void print_vec(vector<int> V)\fake[;]\
\hide[
{
for (int i=0; i<V.size(); i++)
cout << V[i] << " ";
cout << endl;
}
]\

// complete this function to reverse a vector
void reverse(\[vector<int>& v]\) {
\[
for (int i=0; i<v.size()/2; i++)
swap(v[i], v[v.size()-i-1]);
]\
}

int main() {
vector<int> test;
int x;
while (cin >> x) test.push_back(x);
cout << "Before reverse: "; print_vec(test);
reverse(test);
cout << "After reverse: "; print_vec(test);
}

Java test suite
See manual

C++ test suite
json list of stdin/args tests
e.g. [{"stdin":"hi", "args":["4", "5"]}, {"stdin":"noargs"}]
to just run once with no input use [{}]

[
{"stdin": "1 0 3"},
{"stdin": "4 8 15 16 23 42"},
{"stdin": "9 6 7 1 1 1 1"}
]

C++ test suite
See manual

Forbidden substrings
json list of strings
e.g. ["for","while"]

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Solution visibility remove
Java imports
json list of importables
e.g. ["java.util.*"]

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Override Java classname
else defaults to
websheet name
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Dependent on other websheets?
json list of websheet names in this folder
e.g. ["DataStructure"]

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Is example?
i.e., just a demo
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Add compiler flag(s)
json list of flags
e.g. ["-Wno-unused-variable"]

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Remove default compiler flag(s)
json list of flags
see default_cppflags
e.g. ["-Wno-write-strings"]

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Property	Value
Description html markup shown to student	Write a function that reverses a vector that is passed in by reference. E.g., if <tt>vec</tt> contains 2, 0, 1, 5 in that order, after calling <tt>reverse(vec)</tt>, it should contain 5, 1, 0, 2 in that order. <br> Call the <tt>swap</tt> function defined previously to help you.
Epilogue html markup shown when solved	remove
Public permissions	remove
Remarks Comments, history, license, etc.	remove
Engine
Choices json list of string, bool pairs e.g. `[["good", true], ["bad", false]]`
Correct answer
Template / Reference solution
Template / Reference solution	#include <iostream> #include <vector> using namespace std; // assume this is defined for you void swap(int& a, int& b)\fake[;]\ \hide[ { int tmp = a; a = b; b = tmp; } ]\ // for testing: print contents of vector void print_vec(vector<int> V)\fake[;]\ \hide[ { for (int i=0; i<V.size(); i++) cout << V[i] << " "; cout << endl; } ]\ // complete this function to reverse a vector void reverse(\[vector<int>& v]\) { \[ for (int i=0; i<v.size()/2; i++) swap(v[i], v[v.size()-i-1]); ]\ } int main() { vector<int> test; int x; while (cin >> x) test.push_back(x); cout << "Before reverse: "; print_vec(test); reverse(test); cout << "After reverse: "; print_vec(test); }
Java test suite See manual
C++ test suite json list of stdin/args tests e.g. `[{"stdin":"hi", "args":["4", "5"]}, {"stdin":"noargs"}]` to just run once with no input use `[{}]`	[ {"stdin": "1 0 3"}, {"stdin": "4 8 15 16 23 42"}, {"stdin": "9 6 7 1 1 1 1"} ]
C++ test suite See manual
Forbidden substrings json list of strings e.g. `["for","while"]`	remove
Solution visibility	remove
Java imports json list of importables e.g. `["java.util.*"]`	remove
Override Java classname else defaults to websheet name	remove
Dependent on other websheets? json list of websheet names in this folder e.g. `["DataStructure"]`	remove
Is example? i.e., just a demo	remove
Add compiler flag(s) json list of flags e.g. `["-Wno-unused-variable"]`	remove
Remove default compiler flag(s) json list of flags see default_cppflags e.g. `["-Wno-write-strings"]`	remove

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