swap2
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//file:		swap2.cpp
//date:		2004.01.16
//author:	AOU


#include <iostream.h>
#include <string.h>


void swap(int &a, int &b);
void swap(float &a, float &b);
void swap(char a[], char b[]);


void main(void)
  {
    {
    int a, b;
    a = 3;
    b = 4;
    cout << "Initially  a, b = " << a << ' ' << b << endl;
    swap(a, b);
    cout << "After swap a, b = " << a << ' ' << b << endl << endl;
    }

    {
    float a, b;
    a = 3.5;
    b = 4.5;
    cout << "Initially  a, b = " << a << ' ' << b << endl;
    swap(a, b);
    cout << "After swap a, b = " << a << ' ' << b << endl << endl;
    }

    {
    char a[20]="Pittsburg";
    char b[20]="Hello";

    cout << "Initially  a, b = " << a << ' ' << b << endl;
    swap(a, b);
    cout << "After swap a, b = " << a << ' ' << b << endl << endl;
    }
  }


void swap(char a[], char b[])
  {
  cout << "  Entering function\n";
  cout << "  a = " << a << endl;
  cout << "  b = " << b << endl;

  int n1 = strlen(a);
  int n2 = strlen(b);
  int n = n1;
  if (n1 < n2)
    n = n2;
  
  char *temp;
  temp = new char[n+1];

  cout << "  n = " << n << endl;

  strcpy(temp, a);
  cout << "  temp = " << temp << endl;

  strcpy(a, b);
  cout << "  a = " << a << endl;

  strcpy(b, temp);
  cout << "  b = " << b << endl;

  cout << "  Getting out of function\n";
  }


void swap(float &a, float &b)
  {
  float temp;
  temp = a;
  a = b;
  b = temp;
  }


void swap(int &a, int &b)
  {
  int temp;
  temp = a;
  a = b;
  b = temp;
  }

/*
Output:

Initially  a, b = 3 4
After swap a, b = 4 3

Initially  a, b = 3.5 4.5
After swap a, b = 4.5 3.5

Initially  a, b = Pittsburg Hello
  Entering function
  a = Pittsburg
  b = Hello
  n = 9
  temp = Pittsburg
  a = Hello
  b = Pittsburg
  Getting out of function
After swap a, b = Hello Pittsburg

Press any key to continue
*/