challenge-021/paulo-custodio/c/ch-1.c


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/*
Challenge 021

Task #1
Write a script to calculate the value of e, also known as Euler's number and
Napier's constant. Please checkout wiki page for more information.
*/

#include <stdio.h>

double calc_e() {
    double e = 1.0;
    double n = 0.0;
    double prod = 1.0;
    double prev = 0.0;
    while (prev != e) {
        prev = e;
        prod *= ++n;
        e += 1/prod;
    }
    return e;
}

int main() {
    printf("%.14f\n", calc_e());
}