Making a random number guessing game (exit failure? wtf)

**rogster001** · 03-01-2011

So it was the problem of the compiler not the language instruction

I mean at runtime? Or does that still count?

**kmdv** · 03-01-2011

Originally Posted by rogster001

I mean at runtime? Or does that still count?

If code written properly (read: properly according to the stanrdard) was crashing just because of the goto instruction, it was problem of the compiler.

**pYro** · 03-01-2011

goto statements are fine except they are evil. People are pressuring C++ standard boards ( IEEE 'n' stuff ) to remove it from the language as it is considered an illogical statement as it causes an 'illogical' execution flow. Simply put; if you need a goto statement, your code is in need of some TLC. Semantically goto statements can be viewed as sub-functions which breaks the semantics of a function which is a linear code flow.

The truth is goto staments are used internally ( not goto staments exactly but jumps to instructions ) i.e. loops.

**muffinman8641** · 03-03-2011

Code:

#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>

using namespace std;

int rnd(int range);
void seedrnd(void);

int main()
{
    int myguess, compguess, atry=101, gcount=0, rang=100, r=1, i;
    
    while (r ==1)
    {
          gcount=0;
          seedrnd();
          cout << "**************************************" << endl;
          cout << "Welcome to my number-guessing program!" << endl;
          cout << "**************************************" << endl;
          cout << "[press enter to continue] \n\n";
          getchar();
          cout << "I have picked a number between 1 and " << rang << endl;
          cout << "How many guesses do you think you'll need? \n\n";
          cin >> myguess;
          compguess=rnd(rang) + 1;
          cout << "\nOK, here we go... \n";
          while (atry != compguess)
          {
                retry:
                
                gcount++;
                cout << "Enter guess " << gcount << ": " << endl;
                cin >> atry;
                if (atry > compguess) {
                         cout << "Sorry, too high. Guess again. " << endl;
                         goto retry;
                         }
                if (atry < compguess) {
                         cout << "Sorry, too low. Guess again. " << endl;
                         goto retry;
                         }
          cout << "FINALLY! \n\n";
          cout << "You needed " << gcount << " guesses, \n and estimated you would need ";
          cout << myguess;
          cout << ". Thanks for playing. " << endl;
          cout << "Press 1 to play the game again. " << endl;
          cin >> r;
          }
          cout << "\n";
          cout << i << " ";
          }
          return (0);
          }
          int rnd(int range)
          {
              int r;
              r=rand()%range;
              return (r);
              }
              void seedrnd(void)
              {
                   srand((unsigned)time(NULL));
                   }

This one works (thanks to help from my programming class teacher and some tweaking from myself), but I was wondering if there was any way to implement a hint system that displays one of the digits (i.e. the tens or ones place).

**Elysia** · 03-03-2011

Before anything else,
a) Get rid of goto.
b) Indent properly.

**muffinman8641** · 03-03-2011

OK, but I tried it without goto and it loops when you guess.
How do I work around this?
[edit- indent like this?

Code:

 return (0)
      }
          int rnd(int range)
            {
              int r;
              r=rand()%range;
              return (r);
            }
                void seedrnd(void)
                {
                    srand((unsigned)time(NULL));
                }

?]
[edit #2- this is handy for indenting knowledge Wikipedia ftw]

**Elysia** · 03-03-2011

You do it logically! Use loops such as while.
Formulate the proper logic in your mind, ie what is the invariant for which we loop?
That is, what conditions must we satisfy to keep asking?

**muffinman8641** · 03-03-2011

Hint? I can't think of anything! Replacing

Code:

 if (atry > compguess)

with

Code:

 while (atry> compguess)

and removing the gotos did, as I predicted, loop it.
(by the way I accidentally lied. I meant to say that

Code:

 if (atry > compguess) {
                         cout << "Sorry, too high. Guess again. " << endl;
                         }

makes it go to "Finally" as if the guess was wrong AND correct!

**Mr.777** · 03-03-2011

You got MS Visual Studio???

**muffinman8641** · 03-03-2011

No, Dev C++. Imma get a new one though, because I've been informed it's out of date. This makes me sad because I'm used to it. :[

**Elysia** · 03-03-2011

Hint:
What do we want to do?
We want to ask the user to input a number until the user answers correct.
So I ask again: what is our condition for looping? When do we want to keep repeating the question?

**muffinman8641** · 03-03-2011

We want to keep looping it until the user's answer is equal to compguess.
While creates an uncontrollable loop.
If takes us right to the end of the program.
If/Else does the same as if.
I think you might be referencing one I'm not familiar with. For? Not real good at those...

**Elysia** · 03-03-2011

No, while is perfectly fine for these things.
So basically you said it yourself:
Loop until input guess == compguess.
While loops take inverted conditions, since they loop until the condition is false.
That is, we want to loop so long as our condition guess == compguess is not met.

Two ways to do this:
while (!guess == compguess))
or inverting the logic within and removing the not condition
while (guess != compguess)

Now put it into place and watch the magic.

**muffinman8641** · 03-03-2011

What does !guess do? I know != is not equal to, so something related to that?

It's like reverse psychology! You're a wizard!
/thanks

**muffinman8641** · 03-03-2011

Oh God, I feel like a moron.

Code:

while (atry != compguess)
            {
                 retry:                 
                 gcount++;
                 cout << "Enter guess " << gcount << ": " << endl;
                 cin >> atry;
                 if ((atry > compguess) || (atry < 1)) {
                 cout << "Please enter a guess between 1 and " << rang << ". " << endl;
                 goto retry;
                 }
                  while (atry == compguess) {
                           cout << "Sorry, too high. Guess again. " << endl;
                           goto retry;
                           }
                  while (atry == compguess) {
                           cout << "Sorry, too low. Guess again. " << endl;
                           goto retry;
                           }
             cout << "FINALLY! \n\n";

I have no idea what to do with this.
What about the if ((atry > compguess) || (atry < 1)) { section?
Sorry for being annoying, I'm just a little confused.