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  1. #include <iostream>
  2. #include <cmath>
  3. #include <functional>
  4. #include <iomanip>
  5. using namespace std;
  6.  
  7. double solve(function<double (double)> f, double a, double b, double eps)
  8. {
  9.     if (a > b) swap(a, b);
  10.     while ( abs(a - b) > eps ) {
  11.         double x = (a + b) / 2.0;
  12.         if ( f(a) * f(x) < 0 )
  13.             b = x;
  14.         else a = x;
  15.     }
  16.     return (a + b) / 2.0;
  17. }
  18.  
  19. int main()
  20. {
  21.     auto f1 = [](double x)->double { return 2 * pow(x, 2.0) - pow(0.5, x) - 3; };
  22.     cout << fixed << setprecision(11) << solve( f1, 1, 2, 0.00001 );
  23.     return 0;
  24. }
Success #stdin #stdout 0s 2984KB
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1.30475997925
https://ideone.com/r6n5NY
language:
C++14 (gcc 8.3)
created:
10 years ago
visibility:
public

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