Given a string with no repeated characters generate all the permutations of the string. Also sort the permutations in the lexical order.

#include<iostream.h>

#include<conio.h>

#include<stdio.h>

#include<string.h>

int factorial(int n)

{

      int fact=1;

      for(int i=2;i<=n;i++)

            fact*=i;

      return fact;

}

char str[100];

void swap(int i,int j)

{

      char temp=str[i];

      str[i]=str[j];

      str[j]=temp;

}

void sort(char **perm,int rows)

{

      for(int i=1;i<rows;i++)

      {

            char *temp;

            strcpy(temp,perm[i]);

            for(int j=i-1;j>=0 && strcmpi(temp,perm[j])<0;j--)

                  strcpy(perm[j+1],perm[j]);

            strcpy(perm[j+1],temp);

      }

}

void main()

{

      clrscr();

      int len,fact;

      cout<<"Enter the string:";

      gets(str);

      len=strlen(str);

      fact=factorial(len);

      char **permutations = new char*[fact];

      for(int i=0;i<fact;i++)

      {

            int j=i%(len-1);

            swap(j,j+1);

            permutations[i]=new char[len];

            strcpy(permutations[i],str);

      }

      for(i=0;i<fact;i++)

            cout<<"\n"<<i+1<<"."<<permutations[i];

      sort(permutations,fact);

      cout<<"\nAFTER SORTING \n";

      for(i=0;i<fact;i++)

            cout<<"\n"<<permutations[i];

      getch();

}