#include <iostream>
void swap(int *x, int *y){
int swap;
swap = *x;
*x = *y;
*y = swap;
}
void swap(char *x, char *y){
char swap;
swap = *x;
*x = *y;
*y = swap;
}
void swap(double *x, double *y){
double swap;
swap = *x;
*x = *y;
*y = swap;
}
int main(void){
int num1=20, num2=30;
swap(&num1, &num2);
std::cout<<num1<<' ' <<num2<<std::endl;
char ch1='A', ch2='Z';
swap(&ch1, &ch2);
std::cout<<ch1<<' ' <<ch2<<std::endl;
double dbl1=1.111, dbl2=5.555;
swap(&dbl1, &dbl2);
std::cout<<dbl1<<' '<<dbl2<<std::endl;
return 0;
}