Task: An integer N is given (entered from the keyboard). Calculate the amount from n terms:

# define _crt_secure_no_warnings
#Include & lt; iostream & gt;
#Include & lt; math.h & gt;
#Include & lt; stdlib.h & gt;
#Include & lt; malloc.h & gt;
INT MAIN () {
SETLOCALE (LC_ALL, "RUS");
int n, y = 1, m = 0;
Printf ("Enter N:"); Scanf ("% d", & amp; n);
While (N! = 0) {// Factorial
    y = y * n;
    n = n - 1;
}
While (N! = 0) {// Danger
  m = m + ((n + n + 1) * (n + n + 1));
  n = n - 1;
}
PrintF ("% d", y);
PrintF ("\ N% d", m);
}

So far, I just do the sketch, I encountered a problem that it displays m = 0 and it does not change. What could be a mistake? I do the addition M + some number.

Answer 1, Authority 100%

just carefully write down all the steps (ideone ).
When calculating SUs, you can use the formula, well, okay.

int n, last = 0, f = 1;
Printf ("Enter N:"); Scanf ("% d", & amp; n);
Double Res = 0;
For (int i = 1; i & lt; = n; i ++) {
  f * = i;
  int sum = 0;
  for (int k = last + 1; k & lt; = last + i; k ++)
    SUM + = K;
  Last + = i;
  res + = 1.0 * F / (SUM * SUM);
}
Printf ("% F", RES);

Answer 2, Authority 100%

unsigned int n;
Scanf ("% u", & amp; n);
Double TERM = 1.0, SUM = 1.0;
For (unsigned int k = 2; k & lt; = n; ++ k)
{
  double a = k - 3. + (3. * k + 1.) / (k * k + 1.);
  SUM + = TERM * = A * A / K;
}
Printf ("%. 10LF \ N", SUM);

Full code here .

Answer 3, Authority 50%

You are in the While cycle: reduce n to zero because of this, the second cycle While is simply not performed.

Solve this by creating an additional variable, and in the cycles to use another, although the factorial calculation will be carried out in a separate function