A one-dimensional array of numbers is set, its values ​​must be transferred to a square matrix, but so that the numbers and columns do not repeat.

The number of elements in the array provides the possibility of creating a square matrix. That is, if the numbers 9 then the matrix will be 3 to 3, if 25 then 5 to 5.

while (true)
  { // endless cycle
 System ("CLS"); // Clean the screen
COUT & LT; & LT; "Enter the number of elements" & lt; & lt; Endl;
  CIN & GT; & GT; m;
if (SQRT (M) == (Long Long) SQRT (M)) Break; // Check that the root is an integer
}

The number of repetitive elements cannot exceed the root of all elements. That is, if numbers 9 then the repetitions can be maximum 3 (as the number of rows and columns).

while (true) {
 COUT & LT; & LT; "Enter an array" & lt; & lt; Endl;
 for (int i = 0; i & lt; m; i ++)
{
  While (! (CIN & GT; & GT; (MAS [I])) || (cin.peek ()! = '\ n'))
{
  check ();
}
}
 int repeat = 0;
 for (int i = 0; i & lt; n; i ++)
  {
    for (int j = 0; j & lt; n; j ++)
    {
       if (MAS [i] == MAS [j]) REPEAT ++;
    }}
if (N & GT; = REPEAT) Break;
else {cout & lt; & lt; "From these numbers it is impossible to build a matrix satisfying the assignment condition" & lt; & lt; endl;}
}

My code But without sorting itself:

# include & lt; iostream & gt;
#Include & lt; Cmath & GT;
#Include & lt; Cstdlib & gt;
#InClude & lt; Iomanip & gt;
Using Namespace STD;
Void Check ()
{
  cin.clear ();
  While (cin.get ()! = '\ n');
  COUT & LT; & LT; "Input Error!" & lt; & lt; Endl;
  COUT & LT; & LT; "Repeat input!" & lt; & lt; Endl;
}
INT MAIN ()
{
 While (True) {// Infinite Cycle
 System ("CLS"); // Clean the screen
SetLocale (LC_ALL, "");
int m;
// -------------------
While (True)
  { // endless cycle
 System ("CLS"); // Clean the screen
COUT & LT; & LT; "Enter the number of elements" & lt; & lt; Endl;
  While (! (CIN & GT; & GT; M) || (cin.peek ()! = '\ n'))
{
  check ();
}
if (SQRT (M) == (Long Long) SQRT (M)) Break;
}
// -------------------
INT N = SQRT (M);
INT MAS [M];
// -------------------
While (True) {
 COUT & LT; & LT; "Enter an array" & lt; & lt; Endl;
 for (int i = 0; i & lt; m; i ++)
{
  While (! (CIN & GT; & GT; (MAS [I])) || (cin.peek ()! = '\ n'))
{
  check ();
}
}
 int repeat = 0;
 for (int i = 0; i & lt; n; i ++)
  {
    for (int j = 0; j & lt; n; j ++)
    {
       if (MAS [i] == MAS [j]) REPEAT ++;
    }}
if (N & GT; = REPEAT) Break;
else {cout & lt; & lt; "From these numbers it is impossible to build a matrix of a removable assignment condition" & lt; & lt; endl;}
}
// --------------------------------------- Checking the array
COUT & LT; & LT; "---------------" & lt; & lt; Endl;
for (int i = 0; i & lt; m; i ++)
{
COUT & LT; & LT; MAS [I];
}
COUT & LT; & LT; "---------------" & lt; & lt; Endl;
// !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
// ------------------------------------ In this part requires help
m = 0;
int * mat [n] [n];
for (int i = 0; i & lt; (n); i ++)
 for (int j = 0; j & lt; (n); j ++)
    {
    IF (Mat [i] [j]) {
    Mat [i] [j] = & amp; mas [m];
    m ++;}
    }
COUT & LT; & LT; "---------------" & lt; & lt; Endl;
for (int i = 0; i & lt; (n); i ++)
  {
     for (int j = 0; j & lt; (n); j ++)
  COUT & LT; & LT; (* Mat [i] [j]) & lt; & lt; "\ t";
  COUT & LT; & lt; "\ n";
  }
COUT & LT; & LT; "---------------" & lt; & lt; Endl;
// ------------------------------------
INT MENU;
COUT & LT; & LT; "" & lt; & lt; endl;
COUT & LT; & LT; "Perform the program again? (1-yes, 2-no) \ n";
      CIN & GT; & GT; MENU;
      if (Menu! = 1) Break;
    }
Return 0;
}

Answer 1, Authority 100%

and funny task …
Well, enter a lot of numbers – not mine, so I have this matrix simply generated by chance, change there.

# include & lt; vector & gt;
#Include & lt; iostream & gt;
#InClude & lt; Iomanip & gt;
#Include & lt; Map & GT;
#Include & lt; Cmath & GT;
#Include & lt; assert.h & gt;
Using Namespace STD; 
vector & lt; vector & lt; int & gt; & gt; make (int m, map & lt; int, int & gt; els)
{
  vector & lt; vector & lt; int & gt; & gt; s (m, vector & lt; int & gt; (m, 0));
  vector & lt; vector & lt; int & gt; & gt; f = s;
  // Arrange takes
  int col = 0;
  for (auto & amp; x: els)
  {
    if (x.second & gt; 1)
    {
      for (int j = 0; j & lt; x.second; ++ j)
      {
        s [(col + j)% m] [j] = x.first;
        f [(col + j)% m] [j] = 1;
      }
      col ++;
      x.second = 0;
    }
  }
  // Arrange the rest
  auto it = els.begin ();
  if (it! = els.end ())
    for (int i = 0; i & lt; m; ++ i)
      for (int j = 0; j & lt; m; ++ j)
        if (f [i] [j] == 0)
        {
          while (it- & gt; second == 0) it ++;
          s [i] [j] = it- & gt; first;
          it ++;
        }
  return s;
}
int main (int argc, const char * argv [])
{
  srand (time (0));
  int n = 25;
  int m = sqrt (n) +0.5;
  if (m * m! = n) {cout & lt; & lt; n & lt; & lt; "- not a square! \ n"; return 0; }
  map & lt; int, int & gt; els;
  for (int k, i = 0; i & lt; n; ++ i)
  {
    k = rand ()% 40;
    els [k] ++;
    cout & lt; & lt; k & lt; & lt; "";
  }
  cout & lt; & lt; endl & lt; & lt; endl;
  int dbls = 0, max_dbl = 0;
  for (auto x: els)
  {
    if (x.second & gt; 1) dbls ++;
    if (x.second & gt; max_dbl) max_dbl = x.second;
  }
  if (dbls & gt; m || max_dbl & gt; m) {cout & lt; & lt; "No solution! \ N"; return 0; }
  auto v = make (m, els);
  for (auto r: v)
  {
    for (auto c: r) cout & lt; & lt; setw (2) & lt; & lt; c & lt; & lt; "";
    cout & lt; & lt; endl;
  }
}