Fibonacci numbers in C

This is a discussion on Fibonacci numbers in C within the C Programming forums, part of the General Programming Boards category; <<split from here >> I have a question about the following code: Code: int x = 0, y = 1, ...

  1. #1
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    <<split from here>>

    I have a question about the following code:

    Code:
    int x = 0, y = 1, z;
      int i;
    
      for ( i = 0; i < 10; i++ ) {
        printf ( "F(&#37;d): %d\n", i, x );
        z = x + y;
        y = x;
        x = z;
      }
    I switched the values for x and y so the sequence would display 0 as the first.

    I understand everything except

    Code:
    z = x + y;
    y = x;
    x = z;
    So when it runs through the first time, z becomes 0+1=1. but what I don't understand is how y=x and x=z..

    It seems to me that x equals 0, making y =0, then making z, which is 1 equal x. So you have 0 and 1 again.

    Can anyone explain to me the logic of this sequence?

  2. #2
    Dr Dipshi++ mike_g's Avatar
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    Y gets copied to X, so the smallest number is lost. Z gets copied to Y so the last number result is stored. IE:
    Code:
    x    y     z
    0 + 1 = 1
    1 + 1 = 2
    1 + 2 = 3
    2 + 3 = 5
    3 + 5 = 8
    5 + 8 = 13
    [edit]Oh yeah changed the variable names around in my explanation, but I hope at least it helps explain what your output should look like.
    Last edited by mike_g; 09-28-2007 at 06:32 PM.

  3. #3
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    Yeah, that makes sense. Thanks mike

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