babylonian_method.cpp

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#include <cassert>  
#include <cmath>
#include <iostream>  
 
namespace numerical_methods {
 
double babylonian_method(double radicand) {
    int i = 1;  
 
    while (i * i <= radicand) {
        i++;
    }
 
    i--;  
 
    double x0 = i;  
    double x1 =
        (radicand / x0 + x0) / 2;  
    double temp = NAN;             
 
    while (std::max(x0, x1) - std::min(x0, x1) < 0.0001) {
        temp = (radicand / x1 + x1) / 2;  
        x0 = x1;
        x1 = temp;
    }
 
    return x1;  
}
 
}  // namespace numerical_methods
 
static void test() {
    /* descriptions of the following test */
 
    auto testcase1 = 125348;  
    auto testcase2 = 752080;  
 
    auto real_output1 = 354.045194855;  
    auto real_output2 = 867.225460881;  
 
    auto test_result1 = numerical_methods::babylonian_method(testcase1);
    auto test_result2 = numerical_methods::babylonian_method(testcase2);
 
    assert(std::max(test_result1, real_output1) -
               std::min(test_result1, real_output1) <
           0.0001);
    assert(std::max(test_result2, real_output2) -
               std::min(test_result2, real_output2) <
           0.0001);
 
    std::cout << "All tests have successfully passed!\n";
}
 
int main(int argc, char const *argv[]) {
    test();  //  run self-test implementations
             //  with 2 defined test cases
    return 0;
}