ernie.WPI.EDU> cat class11.C

// file class11.C, cs2223, D97/98 //
// minimum print queuing time problem

// 15Mar98 NW, First version

// includes
#include "headers.h"

// prototype
void selection(int, int *); // selection sort an array

// definition
inline int min(int x, int y) { return x < y ? x : y;}

// main
int main ()
   {
   int times[] = {3, 1, 2, 7}; // print times for four jobs
   int min_time = INT_MAX;
   
   cout << "The set of all possible print orders is" << endl;
   cout << "j1 j2 j3 j4  time" << endl;
   for (int a = 0; a < 4; a++) // loop through jobs
      {
      for (int b = 0; b < 4; b++)
         {
         if (b == a) continue; // avoid duplicates
         for (int c = 0; c < 4; c++)
            {
            if ((c == a) || (c == b)) continue; // avoid duplicates
            for(int d = 0; d < 4; d++)
               {
               if ((d == a) || (d == b) || (d == c)) continue; // avoid duplicates
               int total = 4 * times[a] + 3 * times[b] + 2 * times[c] + times[d];
               min_time = min(min_time, total);
               cout << setw(2) << a+1 << setw(3) << b+1 << setw(3) << c+1 << setw(3) <<
                  d+1 << "  " << total << endl;
               } // end for(d)
            } // end for(c)
         } // end for(b)
      } // end for(a)
   cout << endl << "The minimum of the above set is " << min_time << endl << endl;
   
   selection(4, times); // sort the job times
   int total = 4 * times[0] + 3 * times[1] + 2 * times[2] + times[3];
   cout << "Total time with jobs printed in increasing time order: " << total << endl;
   
   return 0;
   } // end main()

void selection(int n, int *array) // selection sort an array
   { // note: this code is adapted from class 06
   int temp;
   for (int i = 0; i < n - 1; i++)
      for (int j = i + 1; j < n; j++)
         if (array[j] < array[i])
            {
            temp = array[i]; // swap the values
            array[i] = array[j];
            array[j] = temp;
            }
   return;
   } // end selection()

// Copyright 1998 Norman Wittelsernie.WPI.EDU> g++ class11.C

ernie.WPI.EDU> a.out

The set of all possible print orders is
j1 j2 j3 j4  time
 1  2  3  4  26
 1  2  4  3  31
 1  3  2  4  27
 1  3  4  2  33
 1  4  2  3  37
 1  4  3  2  38
 2  1  3  4  24
 2  1  4  3  29
 2  3  1  4  23
 2  3  4  1  27
 2  4  1  3  33
 2  4  3  1  32
 3  1  2  4  26
 3  1  4  2  32
 3  2  1  4  24
 3  2  4  1  28
 3  4  1  2  36
 3  4  2  1  34
 4  1  2  3  41
 4  1  3  2  42
 4  2  1  3  39
 4  2  3  1  38
 4  3  1  2  41
 4  3  2  1  39

The minimum of the above set is 23

Total time with jobs printed in increasing time order: 23

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