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The problem

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

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

His mom appears out of a window 1.5 meters from the bottom.

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

Three circumstances have to be met for a sound experiment:

• Float parameter “h” in meters have to be higher than 0
• Float parameter “bounce” have to be higher than 0 and fewer than 1
• Float parameter “window” have to be lower than h.

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

Be aware:

The ball can solely be seen if the peak of the rebounding ball is strictly higher 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:

#embody <stdio.h>
#embody <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:

#embody <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 okay;
    for(okay=h*bounce; okay>window; okay*=bounce) occasions+=2;
    return occasions;
}

Check instances to validate our answer

#embody <stdlib.h>
#embody <time.h>
#embody <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 obtained %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 okay = 0; okay < 100; okay++) {
        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);
}