How to cout a float number with n decimal places [duplicate]
Solution 1:
You need std::fixed and std::setprecision:
std::cout << std::fixed << std::setprecision(3) << a;
These require following header:
#include <iomanip>
Solution 2:
Try setprecision:
cout.setf(ios::fixed);
cout << setprecision(3) << a << endl;