Long Numbers

i am trying to print in standard notation but it keeps printing in scientific notation. here is the coding.

Code:

---

#include <iostream>
using namespace std;

int main()
{
        long double no1, no2, ans;
    char ch1;

        cout << "Enter an equation:";

        cin >> no1 >> ch1 >> no2;

    if (ch1 == '+')
    {
                ans = no1 + no2;
    }
    if (ch1 == '-')
    {
        ans = no1 - no2;
    }
   
    cout<<ans<<endl;
   
        return 0;
}

---

i am trying to get
123456789012345678901234567890 + 12345678901234567890
as the input to output
246913578024691357802469135780

Try using manipulators to change how floating point values are output. The catch is you need to use the manipulator every time you output a value (as the stream typically gets reset to defaults once the value is output)

Code:

---

  cout << fixed << setw(20) << ans << endl;

---

std::fixed is a manipulator that outputs floating point in fixed notation. std::setw() sets the width of the output for the next value.

all this is doing is puttin a space of 50 chars in front of the scientific notation answer, it doesnt change it to standard notation. please help this is killing me.

Code:

---

#include <iostream>
#include <iomanip>
using namespace std;

int main()
{
        long double no1, no2, ans;
    char ch1;

        cout << "Enter an equation:";

        cin >> no1 >> ch1 >> no2;

    if (ch1 == '+')
    {
                ans = no1 + no2;
    }
    if (ch1 == '-')
    {
        ans = no1 - no2;
    }
   
    cout <<  setw(50) << ans <<endl;
   
        return 0;
}

---

As far as I know, you can use cout.precision(int n) to change the number of digits it displays, but careful about the maximum precision of the data type itself.

k i got that but now if my answer doesnt fill the (int n) it puts zeros at the end of the answer