Swap string

#include<stdio.h>
#include<string.h>
#include<malloc.h>
#include<conio.h>
main()
{
   char first[100], second[100], *temp;
    printf("Enter the first string ");
   gets(first);
    printf("Enter the second string ");
   gets(second);
    printf("\nBefore Swapping\n");
   printf("First string: %s\n",first);
   printf("Second string: %s\n\n",second);
    temp = (char*)malloc(100);
    strcpy(temp,first);
   strcpy(first,second);
   strcpy(second,temp);
    printf("After Swapping\n");
   printf("First string: %s\n",first);
   printf("Second string: %s\n",second);
   getch();
   return 0;
}

Output:
Enter the first string: abc
Enter the second string: def
Before Swapping
First string:abc
Second string:def
After Swapping
First string:def
Second string:abc