How one can Resolve Deodorant Evaporator in C

The problem

This program checks the lifetime of an evaporator containing a gasoline.

We all know the content material of the evaporator (content material in ml), the share of froth or gasoline misplaced each day (evap_per_day) and the edge (threshold) in share past which the evaporator is now not helpful. All numbers are strictly sure.

This system reviews the nth day (as an integer) on which the evaporator will likely be out of use.

Instance:

evaporator(10, 10, 5) -> 29

Word:

Content material is actually no longer important within the frame of the serve as “evaporator”, you’ll use it or no longer use it, as you would like. Some folks would possibly like to explanation why with content material, another with percentages handiest. It’s as much as you however you will have to stay it as a parameter since the checks have it as a controversy.

The answer in C

Possibility 1:

#come with <math.h>

int evaporator(double content material, double evap_per_day, double threshold) {
  go back (int) ceil(log(threshold/100) / log(1 - evap_per_day/100));
}

Possibility 2:

int evaporator(double content material, double evap, double threshold) {
    unsigned brief n = 0;
    for(go with the flow misplaced = content material * (threshold/100); content material > misplaced; n++)
      content material -= content material * (evap/100);
    go back n;
}

Possibility 3:

int evaporator(double content material, double evap_per_day, double threshold) {    
    int days;
    double share = 100;
    
    for(days = 0; share>=threshold; days++) {
      share *= (1-(evap_per_day/100));
    }     
    go back days;
}

Take a look at instances to validate our answer

#come with <criterion/criterion.h>

extern int evaporator(double content material, double evap_per_day, double threshold);

static void do_test(double content material, double evap_per_day, double threshold, int anticipated)
{
	int exact = evaporator(content material, evap_per_day, threshold);

	cr_assert_eq(exact, anticipated,
		"content material = %fn"
		"evap_per_day = %fn"
		"threshold = %fn"
		"anticipated %d, however were given %d",
		content material, evap_per_day, threshold,
		anticipated, exact
	);
}

Take a look at(tests_suite, sample_tests)
{
    do_test(10, 10, 10, 22);
    do_test(10, 10, 5, 29);
    do_test(100, 5, 5, 59);
    do_test(50, 12, 1, 37);
    do_test(47.5, 8, 8, 31);
    do_test(100, 1, 1, 459);
    do_test(10, 1, 1, 459);
    do_test(100, 1, 5, 299);
}