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[renzokuzen]

Well, i would like to make a program which asks the user to enter four number and i will then display the smallest number. Sadly, im stuck and i do not know how to continue. Can anyone help me?

#include <iosteam.h>
#include <conio.h>

void main()
{
   clrscr()
   int a, b, c, d;
   cout << "Please enter the first number: ";
   cin >> a;
   cout << "\n Please enter the second number: ";
   cin >> b;
   cout << "\n Please enter the third number: ";
   cin >> c;
   cout << "\n Please enter the fourth number: \n";
   cin >> d;

   if (a<b)

and im stuck... XD

[Mitsakos]

You should use an array to store your numbers and then a for-loop to check which one is the smallest.

[renzokuzen]

uh.....how???

[Mitsakos]

This explains about arrays:
http://www.cplusplus.com/doc/tutorial/arrays.html

#include <iostream>
using namespace std;
int main(){
   int nums[4]; //Creates an array of 4 integers
   int min; //A value that will store the minimum number
   for(int i=0; i<4; i++){ //For-loop to prompt user to enter values
      cout << "Enter " << i << " number: ";
      cin >> nums[i]; //Read from the console a number to the array
   }
   min = nums[0]; //Set the min to the first number
   for(int i=1; i<4; i++){
      if(num[i] < min) //Check if another value is smaller than min
         min = num[i];
   }
   cout << "Minimum number: " << min << endl; //Display the min
   return 0;
}

[renzokuzen]

well, im having exam but, my lecturer restricts me from using arrays because he said he havent covered that chapter.

[Mitsakos]

Then the easiest way to do it (atleast for me) is when you read a variable to check if it is the minimum.

#include <iostream>
using namespace std;
int main(){
   int a, b, c, d, min;//Added one more variable to hold the minimum number
   cout << "Please enter the first number: ";
   cin >> a;
   min = a;//We assign as min the first number the user enters to have something to compare
   cout << " Please enter the second number: ";
   cin >> b;
   if(b < min) min = b;//We compare each number if it is smaller than the min
                       //If it is then assign to min the new variable
   cout << " Please enter the third number: ";
   cin >> c;
   if(c < min) min = c;
   cout << " Please enter the fourth number: ";
   cin >> d;
   if(d < min) min = d;
   cout << "Minimum number is: " << min << endl; //Print out the minimum
   return 0;
}

[helios]

Oh, well then I guess he wants you to use logical operators:
Operator ! (not): if the operand is zero, the result is non-zero, otherwise, it is zero.

Operator && (and):
0 && 0 == 0
0 && !0 == 0
!0 && 0 == 0
!0 && !0 == !0

Operator || (or):
0 || 0 == 0
0 || !0 == !0
!0 || 0 == !0
!0 || !0 == !0

Operator ^ (xor):
Note: xor behaves slightly different (a difference I won't explain here), so it's best not to use it for logical operations.
0 ^ 0 == 0
0 ^ !0 == !0
!0 ^ 0 == !0
!0 ^ !0 == 0

Needless to say, an expression such as 1<2 is evaluated as !0. You fill the gaps.

EDIT: ^Damn. Beaten by seconds and by an even better method. Well, use whichever you prefer.

[Mitsakos]

I have to admit that i am a little confused on how to use the logic operators in this case...
(just a typing mystake: Operator || is "or" not "and")

[helios]

Thanks. Copy-pasting mistake.
Well, he'd have to use (a<b && a<c && ...). Like I said, your method is better. I do think that's what the guy wanted him to do.

[Mitsakos]

I did't see your edit... :P
I believe it is just a simple example on how to use the if statement.
I was always getting confused with too many conditions in an if statement, so I prefer to use as less as possible.. :D

[helios]

Oh, well then I guess you never used a Karnaugh's map (http://en.wikipedia.org/wiki/Karnaugh) to obtain the formulas generating truth tables. You can get some preeety complex expressions.
Well, I feel kinda verbose, so...
!a && !b == !(a || b)
!a || !b == !(a && b)

[Mitsakos]

I used the Karnaugh's map very much for my electronic engineering class in Digital Circuits...
I understand logic operators very well, and they can be really complex as you sayed, but in programming I prefer to write code that I can read easier. So less conditions in one if makes me read it better... :D