46 lines
1.2 KiB
C++
46 lines
1.2 KiB
C++
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#include <iostream>
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#include <math.h>
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using namespace std;
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double karatsuba(double num1, double num2) {
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int num1Length = to_string((int)num1).size();
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int num2Length = to_string((int)num2).size();
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// Fallback to traditional multiplication
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if (num1Length == 1 || num2Length == 1) {
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return num1 * num2;
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} else {
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double n = floor(max(num1Length, num2Length) / 2);
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double lowNum1 = fmod(num1, pow(10, n));
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double lowNum2 = fmod(num2, pow(10, n));
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double highNum1 = floor(num1 / pow(10, n));
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double highNum2 = floor(num2 / pow(10, n));
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double z0 = karatsuba(lowNum1, lowNum2);
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double z1 = karatsuba(lowNum1 + highNum1, lowNum2 + highNum2);
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double z2 = karatsuba(highNum1, highNum2);
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return (z2 * pow(10, n * 2)) + ((z1 - z2 - z0) * pow(10, n)) + z0;
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}
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}
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int main() {
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cout << "Give me a number! ";
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double num1;
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cin >> num1;
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cout << "Give me a number to multiply " + to_string(num1) + " by! ";
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double num2;
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cin >> num2;
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double karatsubaResult = karatsuba(num1, num2);
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double quadraticResult = num1 * num2;
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cout << endl << "Quadratic Result: " + to_string(quadraticResult) << endl;
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cout << "Karatsuba Result: " + to_string(karatsubaResult);
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}
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