Thread: Why does my program not start?

Hi!
First of all, I know that my code in regard to solving the task (logic) is still wrong and I will deal with it afterwards.
For now, I am stuck at the technical details, since my program is even not starting and apparently not entering the main function and I do wonder why not?
Has it something to do with the fact that the return type of my function shall be a double value, whereas the return type of the main function shall be an integer value?

Code:

#include <stdio.h>

double ln2iter(int number_subtotals) {
    int i, j;
    double base = -1, numerator = 1, sum = 0;
    for (i = 1; i < (number_subtotals + 1); i++) {
        numerator *= base;
    } for (j = 1; j <= number_subtotals; j++) {
        sum = sum + ((numerator) / j);
    }
    return sum;
}




 int main() {
     int n;
     double result;


     printf("How many subtotals do you want to have calculated?\n");
     scanf("%d", &n);
     result = ln2iter(n);
     printf("The natural logarithm of 2 with %d subtotals is %lf.\n", n, result);


     return 0;
}

Originally Posted by flp1969

As a program, there are no errors, except the %lf format at printf... %f will always deal with double... and to deal with long double you have to use %Lf (uppercase L). This is not this case. How are you compiling and linking your program?

I just use for testing the codeblocks workspace where all happens automatically.

As the intention of the program, your function is completely wrong... Use log(), from libm, to get the ln 2: log(2.0) and compare the results.

PS: Get the glibc source code and take a look at sysdeps/ieee754/flt-32/e_logf.c to see the complexity of log(x).

Thanks for the suggestions - I will take a look and try to understand the sourcecode myself.