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Functions in C++ can only return 1 value. What if we want to return 2 or more values?


Write a function that returns the sum and difference (a-b) of two integers.
At least one value will have to be passed by reference and then set by the function via a pointer. We usually
calls these parameters (that are passed via pointer so they can be set by a function) an output parameter.

You may choose which value you return and which you pass by reference.

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Copied from problem cpp/pointers/roll2 (author: redekopp@usc.edu)
Originally by Mark Redekopp (redekopp@usc.edu) and Dave Pritchard (daveagp@gmail.com)

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

Correct answer
Template / Reference solution

Template / Reference solution

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

// computes and returns the sum and difference of a and b.
\[int ]\ sum_diff(int a, int b, \[int* d]\)
{
\[
*d = a - b;
return a+b;
]\
}

int main() {
int x, y; // two integers
int sum, diff;

cin >> x >> y;
\[
sum = sum_diff(x, y, &diff);
]\
cout << sum << " " << diff << endl;

return 0;
}

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" : "2 3"},
{ "stdin" : "-1 4" }
]

C++ test suite
See manual

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Property	Value
Description html markup shown to student	<p>Functions in C++ can only return 1 value. What if we want to return 2 or more values?</p> <p></p> <p>Write a function that returns the sum and difference (a-b) of two integers.</p> <p>At least one value will have to be passed by reference and then set by the function via a pointer. We usually calls these parameters (that are passed via pointer so they can be set by a function) <b>an output parameter</b>.</p> <p>You may choose which value you return and which you pass by reference.</p>
Epilogue html markup shown when solved	remove
Public permissions	remove
Remarks Comments, history, license, etc.	Copied from problem cpp/pointers/roll2 (author: redekopp@usc.edu) Originally by Mark Redekopp (redekopp@usc.edu) and Dave Pritchard (daveagp@gmail.com) 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 <cstdlib> using namespace std; // computes and returns the sum and difference of a and b. \[int ]\ sum_diff(int a, int b, \[int* d]\) { \[ *d = a - b; return a+b; ]\ } int main() { int x, y; // two integers int sum, diff; cin >> x >> y; \[ sum = sum_diff(x, y, &diff); ]\ cout << sum << " " << diff << endl; return 0; }
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" : "2 3"}, { "stdin" : "-1 4" } ]
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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