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Commit 63c1a6a

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Simplify operators exercise
* provide definition of normalize() * provide two data members for numerator and denominator * remove addition operators * do not check whether *= can be chained
1 parent 22c7860 commit 63c1a6a

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2 files changed

+16
-73
lines changed

2 files changed

+16
-73
lines changed

‎code/operators/operators.cpp‎

Lines changed: 15 additions & 29 deletions
Original file line numberDiff line numberDiff line change
@@ -1,18 +1,29 @@
11
#include <iomanip>
22
#include <iostream>
3+
#include <numeric>
34

45
class Fraction {
6+
public:
57
// TODO: constructors and operators
8+
9+
private:
10+
void normalize() {
11+
const int gcd = std::gcd(m_num, m_denom);
12+
m_num /= gcd;
13+
m_denom /= gcd;
14+
}
15+
16+
int m_num, m_denom;
617
};
718

8-
// TODO:operators
19+
// TODO:operators
920

1021

11-
void printAndCheck(conststd::string & what, constFraction & result, constFraction & expected) {
22+
void printAndCheck(std::string const& what, Fraction const& result, Fractionconst & expected) {
1223
const bool passed = result == expected;
1324
std::cout << std::left << std::setw(40) << what << ": " << (passed ? "PASS" : "** FAIL **") << " " << result << "\n";
1425
}
15-
void printAndCheck(conststd::string & what, bool result, bool expected) {
26+
void printAndCheck(std::stringconst & what, bool result, bool expected) {
1627
const bool passed = result == expected;
1728
std::cout << std::left << std::setw(40) << what << ": " << (passed ? "PASS" : "** FAIL **") << " " << result << "\n";
1829
}
@@ -36,45 +47,20 @@ int main() {
3647
printAndCheck("Three times one third", three * athird, Fraction{1, 1});
3748
// normalize the fraction after multiplication so the above statement
3849
// prints 1/1 instead of e.g. 3/3
39-
// you might need to compute the greatest common divisor, for which you can
40-
// use the function std::gcd(a, b) from the <numeric> header
4150
printAndCheck("Three times one third", 3 * athird, Fraction{1, 1});
4251

4352
// multiply in place
4453
Fraction f = athird;
4554
f *= 2;
4655
printAndCheck("One third times two", f, Fraction{2, 3});
4756

48-
f = athird;
4957
f *= athird;
50-
printAndCheck("One third times one third", f, Fraction{1, 9});
51-
52-
f = athird;
53-
f *= f *= f;
54-
printAndCheck("One third times itself twice", f, Fraction{1, 81});
58+
printAndCheck("One third times one third", f, Fraction{2, 9});
5559

5660
// you might have some redundancy between the implementation of operator* and
5761
// operator*=. Can you refactor your code and implement operator* in terms of
5862
// operator*=?
5963

60-
// add an int to a fraction
61-
printAndCheck("One third plus 2", athird + 2, Fraction{7, 3});
62-
// ensure symmetry
63-
printAndCheck("2 plus one third", 2 + athird, Fraction{7, 3});
64-
65-
// add two fractions
66-
printAndCheck("One third plus two sixth", athird + Fraction{2, 6}, Fraction{2, 3});
67-
// normalize the fraction after addition too so the above statement
68-
// prints 2/3 instead of 12/18
69-
// make sure the normalization between addition and multiplication is not
70-
// duplicated, e.g. by putting it into a separate method
71-
72-
// add in place
73-
f = athird;
74-
f += f += 1;
75-
printAndCheck("One third plus one and added to itself", f, Fraction{8, 3});
76-
// again, try to refactor and implement operator+ in terms of operator+=
77-
7864
std::cout << std::boolalpha; // print bools as 'true' or 'false' from now on
7965

8066
// more equality comparisons

‎code/operators/solution/operators.sol.cpp‎

Lines changed: 1 addition & 44 deletions
Original file line numberDiff line numberDiff line change
@@ -1,4 +1,3 @@
1-
#include <cassert>
21
#include <iomanip>
32
#include <iostream>
43
#include <numeric>
@@ -32,23 +31,6 @@ class Fraction {
3231
friend Fraction operator*(int i, Fraction const & f) { return f * i; }
3332
friend Fraction operator*(Fraction a, Fraction const & b) { return a *= b; }
3433

35-
Fraction & operator+=(int i) {
36-
m_num += i * m_denom;
37-
return *this;
38-
}
39-
40-
Fraction & operator+=(Fraction o) {
41-
m_num *= o.m_denom;
42-
m_num += o.m_num * m_denom;
43-
m_denom *= o.m_denom;
44-
normalize();
45-
return *this;
46-
}
47-
48-
friend Fraction operator+(Fraction r, int i) { return r += i; }
49-
friend Fraction operator+(int i, Fraction const & r) { return r + i; }
50-
friend Fraction operator+(Fraction a, Fraction const & b) { return a += b; }
51-
5234
friend bool operator==(Fraction const & a, Fraction const & b) {
5335
return a.m_num == b.m_num && a.m_denom == b.m_denom;
5436
}
@@ -100,45 +82,20 @@ int main() {
10082
printAndCheck("Three times one third", three * athird, Fraction{1, 1});
10183
// normalize the fraction after multiplication so the above statement
10284
// prints 1/1 instead of e.g. 3/3
103-
// you might need to compute the greatest common divisor, for which you can
104-
// use the function std::gcd(a, b) from the <numeric> header
10585
printAndCheck("Three times one third", 3 * athird, Fraction{1, 1});
10686

10787
// multiply in place
10888
Fraction f = athird;
10989
f *= 2;
11090
printAndCheck("One third times two", f, Fraction{2, 3});
11191

112-
f = athird;
11392
f *= athird;
114-
printAndCheck("One third times one third", f, Fraction{1, 9});
115-
116-
f = athird;
117-
f *= f *= f;
118-
printAndCheck("One third times itself twice", f, Fraction{1, 81});
93+
printAndCheck("One third times one third", f, Fraction{2, 9});
11994

12095
// you might have some redundancy between the implementation of operator* and
12196
// operator*=. Can you refactor your code and implement operator* in terms of
12297
// operator*=?
12398

124-
// add an int to a fraction
125-
printAndCheck("One third plus 2", athird + 2, Fraction{7, 3});
126-
// ensure symmetry
127-
printAndCheck("2 plus one third", 2 + athird, Fraction{7, 3});
128-
129-
// add two fractions
130-
printAndCheck("One third plus two sixth", athird + Fraction{2, 6}, Fraction{2, 3});
131-
// normalize the fraction after addition too so the above statement
132-
// prints 2/3 instead of 12/18
133-
// make sure the normalization between addition and multiplication is not
134-
// duplicated, e.g. by putting it into a separate method
135-
136-
// add in place
137-
f = athird;
138-
f += f += 1;
139-
printAndCheck("One third plus one and added to itself", f, Fraction{8, 3});
140-
// again, try to refactor and implement operator+ in terms of operator+=
141-
14299
std::cout << std::boolalpha; // print bools as 'true' or 'false' from now on
143100

144101
// more equality comparisons

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