問題
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.
制約
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.
例
入力:
first = [1, 6]
second = [1, 4]
exponent = 0
operation = "add"
期待される出力:
expected = [5, 12]
入力:
std::vector<long long> first = {1, 6};
std::vector<long long> second = {1, 4};
long long exponent = 0;
std::string operation = "add";
期待される出力:
std::vector<long long> expected = {5, 12};
入力:
long[] first = new long[] {1, 6};
long[] second = new long[] {1, 4};
long exponent = 0;
string operation = "add";
期待される出力:
long[] expected = new long[] {5, 12};
解説
1/6 + 1/4 = 2/12 + 3/12 = 5/12, already reduced.
入力:
first = [2, 3]
second = [0, 1]
exponent = -2
operation = "power"
期待される出力:
expected = [9, 4]
入力:
std::vector<long long> first = {2, 3};
std::vector<long long> second = {0, 1};
long long exponent = -2;
std::string operation = "power";
期待される出力:
std::vector<long long> expected = {9, 4};
入力:
long[] first = new long[] {2, 3};
long[] second = new long[] {0, 1};
long exponent = -2;
string operation = "power";
期待される出力:
long[] expected = new long[] {9, 4};
解説
A negative exponent inverts the fraction: (2/3)⁻² = (3/2)² = 9/4.
解き方のヒント
まずは自分で考えてから、ヒントを 1 つずつ開いてみましょう。
ヒント 1
Convert each fraction to a common representation and combine the numerators according to the chosen operation.
ヒント 2
After the operation, reduce the result by dividing by the greatest common divisor and make the denominator positive.
ヒント 3
Watch special cases like zero results, absolute value, and the power rule’s zero and negative exponents.
目安の計算量
O(log n) time, O(1) extra space
参考資料
この課題はCodeUtility用に調整されています。上記の説明と制約に従ってください。