-
Notifications
You must be signed in to change notification settings - Fork 1
/
fractionMath.ts
75 lines (63 loc) · 2.2 KB
/
fractionMath.ts
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
/*
Write a function that can do the 4 basic operations (add, subtract, multiply and divide) on two fractions.
Return the most simplified form of the result.
You can assume a non-zero denominator in the input, and don’t use any built-in implementations in your language of choice, if you can!
Example:
> fractionMath("3/4", "add", "3/4")
> "3/2"
> fractionMath("1/8", "multiply", "2/2")
> "1/8"
*/
type Fraction = `${number}/${number}`;
type Operation = 'add' | 'subtract' | 'multiply' | 'divide';
type OperationFunc = (f1: Fraction, f2: Fraction) => Fraction;
type OperationsMap = Record<Operation, OperationFunc>;
type Formula = (a: number, b: number, c: number, d: number) => [number, number];
// Greatest Common Divisor
function calculateGcd(num1: number, num2: number): number {
if (num2 === 0) {
return num1;
}
return calculateGcd(num2, num1 % num2);
}
function simplifyFraction(numerator: number, denominator: number) {
const gcd = calculateGcd(numerator, denominator);
return [numerator / gcd, denominator / gcd];
}
function solveOperation(f1: Fraction, f2: Fraction, formula: Formula): Fraction {
// parse string fractions
const [a, b] = f1.split('/').map(Number);
const [c, d] = f2.split('/').map(Number);
// apply formula
const [partialNumerator, partialDenominator] = formula(a, b, c, d);
// simplify
const [resultNumerator, resultDenominator] = simplifyFraction(
partialNumerator,
partialDenominator,
);
// stringify fraction
return `${resultNumerator}/${resultDenominator}`;
}
const OPERATIONS: OperationsMap = {
add(f1: Fraction, f2: Fraction) {
return solveOperation(f1, f2, (a, b, c, d) => [a * d + b * c, b * d]);
},
subtract(f1: Fraction, f2: Fraction) {
return this.add(f1, this.multiply('-1/1', f2));
},
multiply(f1: Fraction, f2: Fraction) {
return solveOperation(f1, f2, (a, b, c, d) => [a * c, b * d]);
},
divide(f1: Fraction, f2: Fraction) {
const [numerator2, denominator2] = f2.split('/').map(Number);
const inverseF2: Fraction = `${denominator2}/${numerator2}`;
return this.multiply(f1, inverseF2);
},
};
export function fractionMath(
fraction1: Fraction,
operation: Operation,
fraction2: Fraction,
): Fraction {
return OPERATIONS[operation](fraction1, fraction2);
}