Hello! here c++ program. my problem is i need to find the permutation is even and odd. However the value +1 (even )and -1(odd) is not appear for each permutation.

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#include    <stdio.h>
#include    <stdlib.h>
#include <iostream>
#include <memory.h>
#define     MAX 100
char        num[MAX + 1];
int         n; 
using namespace std;

int sign(int n)
{ int num[MAX];
int g,h,l;
for(g=1,l=1;g<n-1; g++)
for (h=g+1;h<n; h++)
{
	if(num[h]<num[g])
		l*=-1;
}
return (l);
}

void rightRotate (int k, int n)
{
    char    temp [2*MAX], *saveptr;
    saveptr = num+k; // i change it here
	cout << "k" << k << "\n";
    memcpy (temp , saveptr, n);
    memcpy (temp + n , saveptr, n); // reverse
   memcpy (saveptr, temp+n - 1, n); //
}
void createCyclicMatrix ()
{
   char    *p[MAX], temp[2*MAX];
    int     i, j, m = 1; 
  memcpy (temp, num + 1, n); // memory function
  memcpy (temp + n , num + 1, n);
    for (i = 0; i <= n; ++i)
        p[i] = temp + n - i;
		m *=sign(n)  ;
		cout << "m "<< m << "\n";
    for (i = 0; i < n; ++i)
       {
        /* print the ith row */
        for (j = 0; j < n; ++j)
            printf ("%d ", *(p[i] + j));
        printf ("\n");
        /* print the ith column */
        for (j = 0; j < n; ++j)
            printf ("%d ", *(p[j] + i));
        printf ("\n");
       }
}

void matrixPermute (int n)
{
    int     i, temp;
   if  (n == 3 ) 
       { 
      createCyclicMatrix ();
      return;
      }
    temp = n-1 ;
	cout<< "temp" <<temp << endl;
    for (i = 1; i<=temp ; ++i) // n-1 times
        {
		//	cout << "i" << i << "\n";
        rightRotate (n-temp +1, temp);
		matrixPermute (temp);
        } 
}
void initiate(char *num, int n)
{
  for (int i = 1; i <=n; ++i) {   // i is a position
    num[i] = i;
  }
} // init

int main ()
{
        cout << "number must be between 3 and 10 \n";
        cin >> n;
		cout  << endl;
	initiate(num , n);
    matrixPermute (n);
}

The best way to do this is with the modulo operator. (%). It returns the remainder of the quotient of 2 integer numbers.

the function 'sign() is not the problem. the problem is value of each permutation is not apper because i use string copy.

thanks. its ok. i can change it

void createCyclicMatrix ()
{
   char    *p[MAX], temp[2*MAX];
    int     i, j, m=1;
  memcpy (temp, num + 1, n); // memory function
  memcpy (temp + n , num + 1, n);
    for (i = 0; i <= n; ++i)
        p[i] = temp + n - i;
m *=sign(n) ;
cout << "m "<< m << "\n";
    for (i = 0; i < n; ++i)
       {
        /* print the ith row */
        for (j = 0; j < n; ++j)
            cout <<*(p[i] + j);
        cout <<"\n";
        /* print the ith column */
        for (j = 0; j < n; ++j)
            cout << *(p[j] + i);
        cout <<"\n";
       }
}

then recall my problem is to find the value (+1 or -1) for each permutation. please help me.

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