prog14_02.cpp

一本语言类编程书籍

// Program 14.2 Exercising the overloaded 'less-than' operators File: prog14_02.cpp
#include <iostream>
#include <cstdlib>               // For random number generator
#include <ctime>                 // For time function
using std::cout;
using std::endl;

#include "Box.h"

// Function to generate random integers from 1 to count
inline int random(int count) {
  return
       1+static_cast<int>(count* static_cast<double>(std::rand()) / (RAND_MAX+1.0));
}

// Display box dimensions
void show(const Box& aBox) {
  cout << endl
       << aBox.getLength() << " by " << aBox.getWidth() << " by " << aBox.getHeight();
}

int main() {
  const int dimLimit = 100;           // Upper limit on Box dimensions
  std::srand((unsigned)std::time(0)); // Initialize the random number generator

  const int boxCount = 20;            // Number of elements in Box array
  Box boxes[boxCount];                // Array of Box objects
  
  for(int i = 0 ; i < boxCount ; i++)
    boxes[i] = Box(random(dimLimit), random(dimLimit), random(dimLimit));

  // Find the largest Box object in the array
  Box* pLargest = &boxes[0];

  for(int i = 1 ; i < boxCount ; i++)
    if(*pLargest < boxes[i])
      pLargest = &boxes[i];

  cout << endl
       << "The largest box in the array has dimensions:";
  show(*pLargest);

  int volMin = 100000.0;            // Lower Box volume limit
  int volMax = 500000.0;            // Upper Box volume limit
  // Display details of Box objects between the limits
  cout << endl << endl 
       << "Boxes with volumes between "
       << volMin << " and " << volMax << " are:";
  for(int i = 0 ; i < boxCount ; i++)
    if(volMin < boxes[i] && boxes[i] < volMax)
      show(boxes[i]);

  cout << endl;
  return 0;
}