Thread: Coin counting (logic problem)

--EDIT--
Sorry about that andyhunter

Kleid-0 - sshhh

won't post any code for that project, but it's a typical learning tool.

Hint. Search your textbook for binary search method.

See, we agree on stuff.

Couldn't find the Binary Search Method in my textbook...
Anyway, I started it...

Code:

#include <iostream.h>
main()
      int guess, ans, ans2;
      int high = 100;
      int low = 1;
      
      cout << "Think of a number between 1 and 100\n";
      cout << "My first guess is 50, is your number higher, lower, or 50?";
      cout << "\n(higher = 1, lower = 2, correct guess = 0)";
      cin >> ans;
      
      if (ans = 1)
         low = 50;
         cout << "My guess is 75, is your number higher, lower, or 75?";
         cout << "\n(higher = 1, lower = 2, correct guess = 0)";
              if (ans2 = 1)
                 high = 100;
                 low = 76;
                 cout << "My guess is 88, is your number higher, lower, or 88?";
                 cout << "\n(higher = 1, lower = 2, correct guess = 0)";
              else
                  if (ans2 = 2)
                  high = 74;
                  low = 51;
                  cout << "My guess is 62, is your number higher, lower, or 62?";
                  cout << "\n(higher = 1, lower = 2, correct guess = 0)";
                  if (ans2 = 0)
                  ???????????
                  ???????????

What would I put where the question marks are, to end the program?
I'm probably starting this wrong anyway. So maybe a few suggestions would help. I started with, if the user entered 1, as in the number is greater than 50.

Actually, I'm in C++ 1, and there will be no C++ 2 next year. So I will not learn more. And it's only a half a year class, so I'm finished with the class in about a week.

Dude, have you been sleeping throught this class?

edit:

Ok here is some psuedocode:

Code:

Set guessnumber = 0
Set a "found" flag to false
Set lower index to min number (your case 0)
Set higher number to max number(your case 100)
while found is false
       guess = (max + min) / 2
       Ask if lower or higher
       if higher then
              min = guess
       if lower than
              max = guess
       if guess = number then
               found = true
       guessnumber = guessnumber + 1
loop
Print I guessed your number in guessnumber tries

This should help.

Look above I edited my post.

Ahhhhh. Let me try this out.

What do you mean by "found", never done that before :x

Just an integer variable indicating a true (1) or false (0) condition to be used in the while loop.

Blah!!! I was sure I got it this time. Anyway, I need help again.
I'm not sure if it's just crashing, or it's closing again. But I tried the getchar();getchar(); and that didn't stop it from closing, so I don't know.

Code:

#include <iostream.h>

main()
{
     int max = 100;
     int min = 1;
     int guess, ans;
     
     cout << "Think of a number between 1 and 100 and I will try to guess it\n";
   do
   {
     guess = (max+min) / 2;
     cout << "My guess is " << guess << ", is your number higher,lower, or 50?\n";
     cout << "(higher = 1, lower = 0, correct guess = 2)";
     
     if (ans = 1)
        min = guess;
     if (ans = 0)
        max = guess;
     if (ans = 2);
   }
   while (ans != 2)
   cout << "I guessed your number!";
   return 0;
}

For those who don't know, The objective of the program was for the user to think of a number between 1 and 100 and the program tries to guess what number it is.

edit:

Code:

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

main()
{
     int max = 100;
     int min = 1;
     int guess, ans;
     
     cout << "Think of a number between 1 and 100 and I will try to guess it\n";
   do
   {
     guess = (max+min) / 2;
     cout << "My guess is " << guess << " is your number higher,lower, or 50?\n";
     cout << "(higher = 1, lower = 0, correct guess = 2)";
     cin >> ans;
     
     if (ans = 1)
        min = guess;
        else
            if (ans = 0)
            max = guess;
                else
                    if (ans = 2)
   }
   while (ans != 2);   
   cout << "I guessed your number!";
   getchar();getchar();
   return 0;
}

Well, I corrected myself, It works good now.
P.S. thanks for the pseudo code!

edit edit: Actually It's still messed up, 0 and 2 don't work, no matter what I press it keeps going as if I went higher.

Here's one solution I wrote a while ago:
The comments, variable names and money is in Swedish, so try to figure the code out as an excercise.

Code:

int main()
{
    using namespace std;
    
    //De här fälten innehåller de sedlar och namn på sedlar vi använder
    //Endast dessa behöver ändras vid en enventuell införsel av Euro
    const int   valorer[]   = {500,100,50,20,10,5,1,0};
    const char* valorNamn[] = {"Femhundralappar","Hundralappar","Femtiolappar","Tjugolappar","Tiokronor",
                               "Femkronor","Enkronor",0};

    //Hämta input
    int belopp, betalat;
    cout << "Skriv in belopp: ";
    cin >> belopp;
    cout << "Skriv in hur mycket du betalar med: ";
    cin >> betalat;

    //Beräkna växel
    int tillbaka = betalat - belopp;

    cout << "Tillbaka " << tillbaka << " kronor" << endl;

    //Gå igenom listan med de olika valörerna
    const int*   valor = valorer;
    const char** namn  = valorNamn;
    while (*valor && *namn)
    {
        //Så här många av denna typ ges tillbaka
        const int antal = tillbaka / *valor;
        //Minska summan med summan vi nu ger tillbaka
        tillbaka = tillbaka % *valor;

        //Visa att vi ger tillbaka 
        cout << *namn << " : " << antal << endl;
        
        ++valor;
        ++namn;
    }
}