fig04_23.cpp

《c＋＋大学教程》源码

// Fig. 4.23: fig04_23.cpp
// Double-subscripted array example.
#include <iostream>

using std::cout;
using std::endl;
using std::fixed;
using std::left;

#include <iomanip>

using std::setw;
using std::setprecision;

const int students = 3;   // number of students
const int exams = 4;      // number of exams

// function prototypes
int minimum( int [][ exams ], int, int );
int maximum( int [][ exams ], int, int );
double average( int [], int );
void printArray( int [][ exams ], int, int );

int main()
{
   // initialize student grades for three students (rows)
   int studentGrades[ students ][ exams ] = 
      { { 77, 68, 86, 73 },
        { 96, 87, 89, 78 },
        { 70, 90, 86, 81 } };

   // output array studentGrades
   cout << "The array is:\n";
   printArray( studentGrades, students, exams );

   // determine smallest and largest grade values
   cout << "\n\nLowest grade: "
        << minimum( studentGrades, students, exams ) 
        << "\nHighest grade: "
        << maximum( studentGrades, students, exams ) << '\n';

   cout << fixed << setprecision( 2 );

   // calculate average grade for each student
   for ( int person = 0; person < students; person++ )
      cout << "The average grade for student " << person 
           << " is " 
           << average( studentGrades[ person ], exams ) 
           << endl;

   return 0;  // indicates successful termination

} // end main

// find minimum grade
int minimum( int grades[][ exams ], int pupils, int tests )
{
   int lowGrade = 100; // initialize to highest possible grade

   for ( int i = 0; i < pupils; i++ ) 

      for ( int j = 0; j < tests; j++ ) 

         if ( grades[ i ][ j ] < lowGrade )
            lowGrade = grades[ i ][ j ];

   return lowGrade;

} // end function minimum

// find maximum grade
int maximum( int grades[][ exams ], int pupils, int tests )
{
   int highGrade = 0;  // initialize to lowest possible grade

   for ( int i = 0; i < pupils; i++ )

      for ( int j = 0; j < tests; j++ )

         if ( grades[ i ][ j ] > highGrade )
            highGrade = grades[ i ][ j ];

   return highGrade;

} // end function maximum

// determine average grade for particular student
double average( int setOfGrades[], int tests )
{
   int total = 0;

   // total all grades for one student
   for ( int i = 0; i < tests; i++ )  
      total += setOfGrades[ i ];

   return static_cast< double >( total ) / tests;  // average

} // end function maximum

// Print the array
void printArray( int grades[][ exams ], int pupils, int tests )
{
   // set left justification and output column heads
   cout << left << "                 [0]  [1]  [2]  [3]";

   // output grades in tabular format
   for ( int i = 0; i < pupils; i++ ) {

      // output label for row
      cout << "\nstudentGrades[" << i << "] ";

      // output one grades for one student
      for ( int j = 0; j < tests; j++ )
         cout << setw( 5 ) << grades[ i ][ j ];

   } // end outer for

} // end function printArray


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 * (C) Copyright 1992-2003 by Deitel & Associates, Inc. and Prentice      *
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