/*
   asst03.cpp
   06/09/2005
   CIS 150
   David Klick
   
   Solution to programming assignment #3.
   This program lets the user guess a number
   that it has chosen randomly. The user gets
   to choose the range (within limits) and then
   guess the random number within that range.
   The program tells the user whether their
   guess is correct, high, or low.
*/

#include <iostream>
#include <cstdlib>
#include <ctime>
using std::cin;
using std::cout;

int main(void) {
   int low, high;  // low and high end of range for guessing
   int num;        // random number to be guessed
   int guess;      // storage for user's guess
   bool done;      // set to true when user chooses to quit
   bool valid;     // used to validate user input
   char choice;    // stores whether user wants to play or quit

   // randomize random number generator
   srand(time(NULL));
      
   cout << "This program will let you guess a number within a range\n";
   done = false;
   while (!done) {
      // get low end of range
      valid = false;
      while (!valid) {
         cout << "Enter low end of range (0-1000): ";
         cin >> low;
         if (low>=0 && low<=1000) {
            valid = true;
         } else {
            cout << "Error: number not within valid range\n";
         }
      }
   
      // get high end of range
      valid = false;
      while (!valid) {
         cout << "Enter high end of range (" << (low+9) << "-10000): ";
         cin >> high;
         if (high>=(low+9) && high<=10000) {
            valid = true;
         } else {
            cout << "Error: number not within valid range\n";
         }
      }

      // choose random number
      num = rand() % (high-low+1) + low;
      cout << "Random number between " << low << " and "
           << high << " has been chosen\n";

      // play guessing game
      cout << "Guess what the number is: ";
      do {
         cin >> guess;
         if (guess < num) {
            cout << "Too low. Guess again: ";
         } else if (guess > num) {
            cout << "Too high. Guess again: ";
         } else {
            cout << "You guessed it!\n";
         }         
      } while (guess != num);

      // find out if user wants to play again
      valid = false;
      cout << "\nPlay again? (Y/N) ";
      do {
         cin >> choice;
         choice = toupper(choice);
         if (choice=='Y' || choice=='N') {
            valid = true;
         } else {
            cout << "That wasn't an option. Play again? (Y/N) ";
         }
      } while (!valid);

      // set done to true if user wants to quit
      if (choice != 'Y') {
         done = true;
      }
   }

   // let user know program has ended normally
   cout << "Thanks for playing\n";
   return 0;
}