C program to swap two strings.

#include<stdio.h>
#include<conio.h>
#include<string.h>
void main()
{
  clrscr();
  int i=0, j=0, k=0;
  char str1[20], str2[20], temp[20];
  printf("Enter the First String : ");
  gets(str1);
  printf("Enter the Second String : ");
  gets(str2);
  printf("Strings before swapping are :\n");
  printf("String 1 = %s\n",str1);
  printf("String 2 = %s\n",str2);
  while(str1[i]!='\0')
  {
 temp[j]=str1[i];
 i++;
 j++;
  }
  temp[j]='\0';
  i=0, j=0;
  while(str2[i]!='\0')
  {
 str1[j]=str2[i];
 i++;
 j++;
  }
  str1[j]='\0';
  i=0, j=0;
  while(temp[i]!='\0')
  {
 str2[j]=temp[i];
 i++;
 j++;
  }
  str2[j]='\0';
  printf("Strings after swapping : \n");
  printf("String 1 : %s\n",str1);
  printf("String 2 : %s\n",str2);
  getch();
}