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Exact Fraction Arithmetic

Perform fraction operations and return a reduced fraction.

What you'll learn

  • Add, subtract, multiply and divide fractions
  • Reduce results with the GCD
  • Normalize signs and zero

Problem

Represent a fraction as [numerator, denominator]. Apply operation to first and second: add, subtract, multiply, or divide. For absolute, use only first. For power, raise first to the integer exponent and ignore second. Return lowest terms with a positive denominator. Normalize zero to [0, 1]. All divisions and negative powers in valid inputs are defined.

Implement rational_arithmetic(operation, first, second, exponent).

Input

operation: The operation name.

first: Two integers representing the first fraction.

second: Two integers representing the second fraction; use [0, 1] when unused.

exponent: The exponent for power; use 0 for other operations.

Output

Return [numerator, denominator] in reduced form with a positive denominator.

Constraints

operation is add, subtract, multiply, divide, absolute, or power. Both fraction components have magnitude at most 100; denominators are nonzero. −6 ≤ exponent ≤ 6. For divide, second has nonzero numerator. For a negative power, first has nonzero numerator. The 0th power is [1, 1], including 0⁰ by this task’s convention. Values fit signed 64-bit.

Examples

Example 1
Input:
first = [1, 6]
second = [1, 4]
exponent = 0
operation = "add"

Expected output:
expected = [5, 12]
Input:
std::vector<long long> first = {1, 6};
std::vector<long long> second = {1, 4};
long long exponent = 0;
std::string operation = "add";

Expected output:
std::vector<long long> expected = {5, 12};
Input:
long[] first = new long[] {1, 6};
long[] second = new long[] {1, 4};
long exponent = 0;
string operation = "add";

Expected output:
long[] expected = new long[] {5, 12};

Explanation

1/6 + 1/4 = 2/12 + 3/12 = 5/12, already reduced.

Example 2
Input:
first = [2, 3]
second = [0, 1]
exponent = -2
operation = "power"

Expected output:
expected = [9, 4]
Input:
std::vector<long long> first = {2, 3};
std::vector<long long> second = {0, 1};
long long exponent = -2;
std::string operation = "power";

Expected output:
std::vector<long long> expected = {9, 4};
Input:
long[] first = new long[] {2, 3};
long[] second = new long[] {0, 1};
long exponent = -2;
string operation = "power";

Expected output:
long[] expected = new long[] {9, 4};

Explanation

A negative exponent inverts the fraction: (2/3)⁻² = (3/2)² = 9/4.

How to approach it

Try on your own first, then open one hint at a time.

Hint 1

Convert each fraction to a common representation and combine the numerators according to the chosen operation.

Hint 2

After the operation, reduce the result by dividing by the greatest common divisor and make the denominator positive.

Hint 3

Watch special cases like zero results, absolute value, and the power rule’s zero and negative exponents.

Expected complexity

O(log n) time, O(1) extra space

References

This challenge is adapted for CodeUtility. Follow the statement and constraints above.

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