C Program to swap two Strings

Program

#include <stdio.h>
void main() {
  int i = 0, j = 0, k = 0;
  char str1[20], str2[20], temp[20];
  printf("Enter first string:\t");
  scanf(" %s", str1);
  printf("Enter second string:\t");
  scanf(" %s", str2);
  printf("Before swaping the strings:\n");
  printf("String 1:\t%s\n", str1);
  printf("String 2:\t%s\n", str2);
  while (str1[i] != '\0') {
    temp[j++] = str1[i++];
  }
  temp[j] = '\0';
  i = 0, j = 0;
  while (str2[i] != '\0') {
    str1[j++] = str2[i++];
  }
  str1[j] = '\0';
  i = 0, j = 0;
  while (temp[i] != '\0') {
    str2[j++] = temp[i++];
  }
  str2[j] = '\0';
  printf("After swaping the strings:\n");
  printf("String 1:\t%s\n", str1);
  printf("String 2:\t%s\n", str2);
}

Output

Enter first string:	welcome
Enter second string:	oodlescoop
Before swaping the strings:
String 1:	welcome
String 2:	oodlescoop
After swaping the strings:
String 1:	oodlescoop
String 2:	welcome