41 lines
771 B
C++
41 lines
771 B
C++
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#include <iostream>
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#include <cmath>
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#include <limits>
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double nthRoot(double n, double x) {
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double lastX;
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double y = 1; // initial guess
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while (y != lastX) {
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// f(y) = yⁿ - x
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// f'(y) = nyⁿ⁻¹
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double f = std::pow(y, n) - x;
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double fprime = n * std::pow(y, n - 1);
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lastX = y;
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y -= f / fprime;
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}
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return y;
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}
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int promptForInteger(std::string letter) {
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std::cout << "Please input a value for " + letter + ": ";
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int input;
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std::cin >> input;
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return input;
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}
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int main() {
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std::cout << "ⁿ√x\n";
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int n = promptForInteger("n");
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int x = promptForInteger("x");
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// Make sure that cout prints to the highest precision possible
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std::cout.precision(std::numeric_limits<double>::max_digits10);
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std::cout << nthRoot(n, x);
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}
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