How to perform rounding using elementary arithmetic operations?
Need to perform rounding to the nearest whole
I have the following code:

int main ()
{
  Double x;
    COUT & LT; & LT; "VVedite Neceloe Chislo =";
  CIN & GT; & GT; x;
    COUT & LT; & LT; "Celaya Chast 'Chisla =";
  // We get a whole part of the number x
  if (x & gt; = 0) cout & lt; & lt; Floor (x) & lt; & lt; Endl;
  if (x & lt; 0) cout & lt; & lt; CEIL (Fabs (X)) & lt; & lt; Endl;
    COUT & LT; & lt; "Okryglennoe do blizhajshego =";
  // The number X, rounded to the nearest whole
  if (x & gt; = 0) cout & lt; & lt; Floor (x) & lt; & lt; Endl;
  if (x & lt; 0) cout & lt; & lt; Ceil (x) & lt; & lt; Endl;
SYSTEM ("PAUSE");
  Return 0;}

Answer 1, Authority 100%

Well, for example …

rounded the number “pi” to three marks after the comma.

double pi = 3.14159265358;
pi = int (pi * 1000 + 0.5) /1000.0;

arrange? 🙂

p.s. You would somehow write more accurately – what numbers, the range, type, how to round – to more, to a smaller, to the nearest … And so – guess what you wanted: (

Update

to the nearest whole – it is rude, up to 0 signs after a comma – so just

int (x + ((x & lt; 0)? -0.5: 0.5))

And in general, this is done by the standard function Round () …