Find out how to Bounce Balls in C

The problem

A baby is enjoying with a ball on the nth ground of a tall constructing. The peak of this ground, h, is thought.

He drops the ball out of the window. The ball bounces (for instance), to two-thirds of its peak (a bounce of 0.66).

His mom seems to be out of a window 1.5 meters from the bottom.

What number of occasions will the mom see the ball move in entrance of her window (together with when it’s falling and bouncing?

Three situations should be met for a sound experiment:

• Float parameter “h” in meters should be better than 0
• Float parameter “bounce” should be better than 0 and fewer than 1
• Float parameter “window” should be lower than h.

If all three situations above are fulfilled, return a optimistic integer, in any other case return -1.

Word:

The ball can solely be seen if the peak of the rebounding ball is strictly better than the window parameter.

Examples:

- h = 3, bounce = 0.66, window = 1.5, result's 3

- h = 3, bounce = 1, window = 1.5, result's -1 

(Situation 2) not fulfilled).

The answer in C

Possibility 1:

#embrace <stdio.h>
#embrace <stdlib.h>

int bouncingBall(double h, double bounce, double window) {
    if ((h <= 0) || (window >= h) || (bounce <= 0) || (bounce >= 1))
        return -1;
    int seen = -1;
    whereas (h > window) {
        seen += 2;
        h = h * bounce;
    }
    return seen;
}

Possibility 2:

#embrace <math.h>

int bouncingBall(double h, double bounce, double window) {
    if (h <= 0 || bounce <= 0 || bounce >= 1 || window >= h) {
      return -1;
    }
    return 2*ceil(log(window/h)/log(bounce)) - 1;
}

Possibility 3:

int bouncingBall(double h, double bounce, double window) {
    if(!(h>0 && bounce>0 && bounce<1 && window<h)) return -1;
    int occasions=1; double ok;
    for(ok=h*bounce; ok>window; ok*=bounce) occasions+=2;
    return occasions;
}

Check circumstances to validate our answer

#embrace <stdlib.h>
#embrace <time.h>
#embrace <criterion/criterion.h>

extern int bouncingBall (double h, double bounce, double window);

static void testequal(double h, double bounce, double window, int anticipated) {
    int precise = bouncingBall(h, bounce, window);
    cr_assert_eq(precise, anticipated,
    "for h = %f, bounce = %f, window = %fn"
    "anticipated %d, however bought %d",
    h, bounce, window,
    anticipated, precise
  );
}

static int answer (double h, double bounce, double window) {
    if ((h <= 0) || (window >= h) || (bounce <= 0) || (bounce >= 1))
        return -1;
    int seen = -1;
    whereas (h > window) {
        seen += 2;
        h = h * bounce;
    }
    return seen;
}

static int randomGen(int a, int b){
    int r = rand();
    return r % (b - a) + a;
}

Check(bouncingBall, randomTests) {       
    srand(time(NULL));

  enum {N = 30};

    const double someheights[N] = {
    12, 10.5, 144, 233, 15.25, 61, 98, 15.9, 25.8, 41.8, 67, 109, 17, 28, 46,
        7.5, 12.20, 19, 3, 5, 83, 13, 21, 35.5, 57, 92, 14, 24, 39, 6.5
  };
    const double someBounces[N] = {
    0.6, 0.6, 0.6, 0.6, 0.6, 1.1, 9, 1, 0.6, 0.6, 0.6, 0.75, 0.75, 0.75, 0.75,
        0.75, 12.20, 0.75, 0.75, 0.83, 0.13, 0.21, 0.35, 0.57, 0.9, 0.14, 0.24, 0.39, 0.65, 0.65
  };
    const double somewin[N] = {
    1.5, 1.5, 1.44, 2.33, 1, 6.1, 9.8, 1.9, 2.8, 4.8, 3, 1.09, 1.7, 2.8, 46, 7.5,
        12.20, 1.9, 3, 5, 0.83, 1.3, 2.1, 3.5, 0.57, 0.92, 1.4, 2.4, 3.9, 6.5
  };

    for (int ok = 0; ok < 100; ok++) {
        int i = randomGen(0, N - 1);
        double h = someheights[i];
        double b = someBounces[i];
        double w = somewin[i];
        testequal(h, b, w, answer(h, b, w));
    }
}

Check(bouncingBall, sampleTests) {       
    testequal(2, 0.5, 1.0, 1);
    testequal(3, 0.66, 1.5, 3);
    testequal(30, 0.66, 1.5, 15);
    testequal(30, 0.75, 1.5, 21);
    testequal(30, 0.4, 10, 3);
    testequal(40, 0.4, 10, 3);
    testequal(10, 0.6, 10, -1);
    testequal(40, 1, 10, -1);
    testequal(-5, 0.66, 1.5, -1);
    testequal(5, -1, 1.5, -1);
    testequal(4, 0.25, 1.0, 1);
}