Thread: big trouble in little program

I keep getting an infinate loop for some reason and I cannot figure out why. This is a Fibonacci program that is a large pain in my ass. I need to add a print function aswell but I am not sure how to go about it. Any ideas. Here is my program.


scanf("%d",&b);
c=cal_fibonacci(b);
}

int cal_fibonacci (int d)
{
int f1;
int f2;
int fnew, temp;
int x;

for(x=1;x<d;++x)
{
while (x<3)
{
printf("%d" "1",x);
printf("F1=1");
printf("F2=1");
}
fnew=f1+f2;
printf("%d" "%d",x,fnew);
f1=temp;
f2=f1;
f2=fnew;
}

}

You forgot to increment the inner loop, therefore the stopping condition is never met and you have an infinite loop.

Code:

    scanf("%d",&b); 
    c=cal_fibonacci(b); 
} 

int cal_fibonacci (int d) 
{ 
    int f1; 
    int f2; 
    int fnew, temp; 
    int x; 

    for(x=1;x<d;x++) 
    { 
        while (x<3) 
        { 
            printf("%d" "1",x); 
            printf("F1=1"); 
            printf("F2=1");
            x += 1;  /* Without an increment, you have an infinite loop */ 
        } 
    fnew=f1+f2; 
    printf("%d" "%d",x,fnew); 
    f1=temp; 
    f2=f1; 
    f2=fnew; 
    } 
}

Your program will also only work once since you're using x as a counter for both loops, it goes through the inner loop once and won't do it again because x will be 3. You can solve a Fibonacci problem with only one loop. Simpler is better.

Code:

long fibonacci ( int n ) {
    long result;
    long previous;
    long next_old;

    result = previous = 1;
  
    while ( n > 2 ) {
        n -= 1;
        next_old = previous;
        previous = result;
        result = previous + next_old;
    }
    return result;
}