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Thread: c++ challange

  1. #1
    Senior Member linuxcomando's Avatar
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    c++ challange

    Thought id give you programers a challeng, Ill post the program prob tommorow.

    De Morgan's Laws can sometimes make it more convenient for us to express a logical expression. These laws state that the expression !(condition1 && condition2) is logically equivalent to the expression (!condition1 ||!condition2). Also the expression !(condition1 || condition2) is logically equivalent to the (!condition1 && !condition2). Use De Morgan's Laws to write equivalent expressions for each of the following then write a program to show that both the original expressions and the new expression in each case are equivalent:
    a) !( x < 5) && !( y >= 7 )
    b) !( a == b) || !(g != 5)
    c) !( ( x <= 8 ) && ( y > 4) )
    d) !( (i > 4 ) || ( j <= 6 ))

  2. #2
    The Iceman Cometh
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    I think these are right (it's been a while since I've used DeMorgan's Law)

    a) !(x < 5) && !(y >= 7) = !((x < 5) || (y >= 7))

    b) !(a == b) || !(g != 5) = !((a == b) && (g != 5))

    c) !((x <= 8) && (y > 4)) = !(x <= 8) || !(y > 4)

    d) !((i > 4) || (j <= 6)) = !(i > 4) && !(j <= 6)

    Sorry, but I don't feel like writing a program right now... Nice idea, though!

    AJ

  3. #3
    Webius Designerous Indiginous
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    a) !( x < 5) && !( y >= 7 )
    b) !( a == b) || !(g != 5)
    c) !( ( x <= 8 ) && ( y > 4) )
    d) !( (i > 4 ) || ( j <= 6 ))


    a)

    !(x<5) && !(y>=7)

    !((x<5)||(y>=7))

    #include <iostream.h>
    int main()
    {
    int x;

    if (!(x<5) && !(y>=7))!=(!((x<5)||(y>=7)))
    {
    cout<<"That's not Right!";
    }
    else
    {
    cout<<"You are correct!";
    }
    return 0;
    }

    I don't have a compiler at work. Does that prog look like it will work? I think it should, but then again i'm still learning c++. I'm not even gunna attempt any more unless this one works. heh
    x

  4. #4
    Senior Member
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    a) !( x < 5) && !( y >= 7 ) == !( x < 5 || y >= 7 )
    b) !( a == b) || !(g != 5) == !( a == b && g != 5 )
    c) !( ( x <= 8 ) && ( y > 4) ) == !( x <= 8 ) || !( y > 4 )
    d) !( (i > 4 ) || ( j <= 6 )) == !( i > 4 ) && !( j <= 6 )

    #include <iostream>
    using namespace std ;
    void main ()
    {
    for( x=0, y=0; x=-1; x++,y++)
    {
    if ( (!( x < 5) && !( y >= 7 )) == (!( x < 5 || y >= 7 )) cout << "bOOOOOOGA\a\t" ;
    else cerr << "blAAAAARRRGH" << endl ;
    }
    }
    Hmm...theres something a little peculiar here. Oh i see what it is! the sentence is talking about itself! do you see that? what do you mean? sentences can\'t talk! No, but they REFER to things, and this one refers directly-unambigeously-unmistakably-to the very sentence which it is!

  5. #5
    i'm very2x confused

  6. #6
    Junior Member
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    The answers simplified as far as they can go are:

    a) x >= 5 && y < 7
    b) a != b || g == 5
    c) x> 8 || y <= 4
    d) i <= 4 && j > 6

    as for the program, i'm too tired at the moment to write it up...

    Chaoswraith

  7. #7
    Senior Member
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    Heh, for a second I just felt like I was back in a first year CS maths course again!
    Don't do that again!

    Ammo
    Credit travels up, blame travels down -- The Boss

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