#include <iostream.h>
#include "CPstring.h"

// file: exhaust4.cc
// demonstrate logical operator &&
// sort by exhaustive checking


int main()
{
   int n1, n2, n3, n4;

   cout << "Enter four numbers." << endl;
   cin >> n1 >> n2 >> n3 >> n4;

   cout << "The numbers, in order, are: ";
   if (n1 < n2 && n2 < n3 && n3 < n4) 
      cout << n1 << " " << n2 << " " << n3 << " " << n4;
   if (n1 < n2 && n2 < n4 && n4 < n3) 
      cout << n1 << " " << n2 << " " << n4 << " " << n3;
   if (n1 < n3 && n3 < n2 && n2 < n4) 
      cout << n1 << " " << n3 << " " << n2 << " " << n4;
   if (n1 < n3 && n3 < n4 && n4 < n2) 
      cout << n1 << " " << n3 << " " << n4 << " " << n2;
   if (n1 < n4 && n4 < n2 && n2 < n3) 
      cout << n1 << " " << n4 << " " << n2 << " " << n3;
   if (n1 < n4 && n4 < n3 && n3 < n2) 
      cout << n1 << " " << n4 << " " << n3 << " " << n2;

   if (n2 < n1 && n1 < n3 && n3 < n4) 
      cout << n2 << " " << n1 << " " << n3 << " " << n4;
   if (n2 < n1 && n1 < n4 && n4 < n3) 
      cout << n2 << " " << n1 << " " << n4 << " " << n3;
   if (n2 < n3 && n3 < n1 && n1 < n4) 
      cout << n2 << " " << n3 << " " << n1 << " " << n4;
   if (n2 < n3 && n3 < n4 && n4 < n1) 
      cout << n2 << " " << n3 << " " << n4 << " " << n1;
   if (n2 < n4 && n4 < n1 && n1 < n3) 
      cout << n2 << " " << n4 << " " << n1 << " " << n3;
   if (n2 < n4 && n4 < n3 && n3 < n1) 
      cout << n2 << " " << n4 << " " << n3 << " " << n1;

   if (n3 < n1 && n1 < n2 && n2 < n4) 
      cout << n3 << " " << n1 << " " << n2 << " " << n4;
   if (n3 < n1 && n1 < n4 && n4 < n2) 
      cout << n3 << " " << n1 << " " << n4 << " " << n2;
   if (n3 < n2 && n2 < n1 && n1 < n4) 
      cout << n3 << " " << n2 << " " << n1 << " " << n4;
   if (n3 < n2 && n2 < n4 && n4 < n1) 
      cout << n3 << " " << n2 << " " << n4 << " " << n1;
   if (n3 < n4 && n4 < n1 && n1 < n2) 
      cout << n3 << " " << n4 << " " << n1 << " " << n2;
   if (n3 < n4 && n4 < n2 && n2 < n1) 
      cout << n3 << " " << n4 << " " << n2 << " " << n1;

   if (n4 < n1 && n1 < n2 && n2 < n3) 
      cout << n4 << " " << n1 << " " << n2 << " " << n3;
   if (n4 < n1 && n1 < n3 && n3 < n2) 
      cout << n4 << " " << n1 << " " << n3 << " " << n2;
   if (n4 < n2 && n2 < n1 && n1 < n3) 
      cout << n4 << " " << n2 << " " << n1 << " " << n3;
   if (n4 < n2 && n2 < n3 && n3 < n1) 
      cout << n4 << " " << n2 << " " << n3 << " " << n1;
   if (n4 < n3 && n3 < n1 && n1 < n2) 
      cout << n4 << " " << n3 << " " << n1 << " " << n2;
   if (n4 < n3 && n3 < n2 && n2 < n1) 
      cout << n4 << " " << n3 << " " << n2 << " " << n1;

   cout << endl;
   return 0;
}

Sample output:

<exhaust3
>Enter four numbers.
<1 2 3 4
>The numbers, in order, are: 1 2 3 4

<exhaust3
>Enter four numbers.
<4 3 2 1
>The numbers, in order, are: 1 2 3 4

<exhaust3
>Enter four numbers.
<1 4 2 3
>The numbers, in order, are: 1 2 3 4

<exhaust3
>Enter four numbers.
<4 1 2 3
>The numbers, in order, are: 1 2 3 4

<exhaust3
>Enter four numbers.
<6 18 2 45
>The numbers, in order, are: 2 6 18 45