// swap1.cc

#include <iostream>
#include <iomanip>

using namespace std;

void swap1 (int i, int j);
void swap2 (int& i, int& j);
void swap3 (int* ip, int* jp);

int main()
{

int i, j;

i = 3;
j = 4;
swap1(i, j);
cout << "a: " << i << " " << j << endl;

i = 3;
j = 4;
swap2(i, j);
cout << "b: " << i << " " << j << endl;

i = 3;
j = 4;
int& ir = i;
int& jr = j;

swap1(ir, jr);
cout << "c: " << ir << " " << jr << endl;
cout << "d: " << i << " " << j << endl;

i = 3;
j = 4;

swap2(ir, jr);
cout << "e: " << ir << " " << jr << endl;
cout << "f: " << i << " " << j << endl;

int* ip;
ip = &i;
int* jp;
jp = &j;

i = 3;
j = 4;

swap3(ip, jp);
cout << "g: " << *ip << " " << *jp << endl;

i = 3;
j = 4;

swap1(*ip, *jp);
cout << "h: " << i << " " << j << endl;

i = 3;
j = 4;

swap2(*ip, *jp);
cout << "i: " << i << " " << j << endl;

return 0;
}

void swap1 (int i, int j)
{ 
int x;
x = i;
i = j;
j = x;
}

void swap2 (int& i, int& j)
{
int x;
x = i;
i = j;
j = x;
}


void swap3 (int* ip, int* jp)
{
int x;
x = *ip;
*ip = *jp;
*jp = x;
}


/* Output:

a: 3 4
b: 4 3
c: 3 4
d: 3 4
e: 4 3
f: 4 3
g: 4 3
h: 3 4
i: 4 3

*/