#include <stdio.h> #include <conio.h> #include <string.h> void main(){ char str[20],tmp; int i,j; clrscr(); printf(\"\\nEnter a string : \"); scanf(\"%s\",str); printf(\"\\n\\nOriginal String : %s\",str); for(i=0;i<strlen(str);i=i+2){ tmp = str[i]; str[i] = str[i+1]; str[i+1] = tmp; } printf(\"\\nAfter Swap String : %s\",str); getch(); }