Do...While Loop problem

Yes, this is a homework problem, but I have already submitted it for a grade, so please don't think I am trying to get you to complete it for me. So, now I am really just trying to learn what I should have done so that I will be able to fix this problem in the future, as I have LabView, Microcontrollers, and VeriLog coming up.

I have a loop that gets the a set of data points. It seems to work fine if I use a for loop, however, I need the loop to continue until the user enters zero (0) for the time input. So, I changed from a for loop to a Do... while loop. I am thinking that the problem is in the loop since that is all that changed, but I am new to using the structures and pointers as well, so my mistake could be located else where.

The commented out sections are a part of my trying to troubleshoot the error. I don't get any data from the Do... While Loop, which makes me think it might be a pointer or structure problem. Again, we just covered structures and pointers in class, so I am new to them.

Thanks for any help that you can offer.

Code:

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#include <stdio.h>
#include <math.h>
#include <stdlib.h>
#include <time.h>


double f(double x);
double monteCarlo(double a, double b, double yMin, double yMax, int trials);
double expectedDoubles(void);
double randDouble(double min, double max);


struct Data {
    float time;
    float accel;
};


void printItem(struct Data pi);
const int MAX = 100;
struct Data points[MAX];


void main(int argc, char* argv[])
{
    int count;
    int i = 0;
    double v;
    int steps = 10000;
    int a, b, yMin, yMax;


    //printf("How many items? ");
    //scanf("%d", &count);


    ////Enter in the data, Time = 0 means quit
    printf("Enter in all data, time = 0 to quit.\n");
    count = 0;
    do {
        printf("Time? ");
        scanf("%f", &points[i].time);
        printf("Accel? ");
        scanf("%f", &points[i].accel);   
        ++count;
    } while (points[i].time != 0);


    //for (i = 0; i < count; ++i) {
    //    printf("Time? ");
    //    scanf("%f", &points[i].time);
    //    printf("Accel? ");
    //    scanf("%f", &points[i].accel);   
    //}


    //Print out the data points
    /*printf("\n\nPrinting Data Points\n");
    for (i = 0; i < count; ++i) {
        printItem(points[i]);*/
    //}


    //Find a,b,yMin,yMax ==> Starting data point is assumed to be 0,0
    a = 0;
    b = points[0].time;
    yMin = 0;
    yMax = points[0].accel;
    for (i = 1; i < count; ++i) {
        if(points[i].time > b){
        b = points[i].time;
        }
        if(points[i].accel > yMax){
        yMax = points[i].accel;
        }
        }


    //Print resulting Velocity
    //Data check
    /*printf("%d, %d, %d, %d\n",a,b,yMin,yMax);*/
    v = monteCarlo(a, b, yMin, yMax, steps);
    printf("Velocity = %.3f [m/s]\n", v);
    getchar();
    getchar();
}


void printItem(struct Data dp) {
    printf("Time: %.2f\n", dp.time);
    printf("Accel: %.2f\n", dp.accel);
    printf("\n\n");
}
double f(double x) {  //function to be integrated
    double v;
    //Vf = V0 + a * t
    v = 0 + x;  //v0 starts at 0 according to the problem & at is replaced by x here
    return v;
}
double monteCarlo(double a, double b, double yMin, double yMax, int trials) {
    double boundryArea = (b - a) * (yMax - yMin);
    int trial;
    double randX, randY;
    int hits = 0;


    srand(time(0));
    for (trial = 0; trial < trials; ++trial) {
        randX = randDouble(a, b);
        randY = randDouble(yMin, yMax);
        if (f(randX) >= 0 && randX >= 0 && randY < f(randX)) {
            ++hits;
        } else if (f(randX) < 0 && randY < 0 && randY > f(randX)) {
            ++hits;
        }
    }
    return (hits / (double) trials) * boundryArea;
}


double randDouble(double min, double max) {
    double r = rand() / (double) (RAND_MAX + 1);
    return r * (max - min) + min;
}


double expectedDoubles(void) {
    const int TRIALS = 10000;
    int trial;
    int die1;
    int die2;
    int rolls;
    int totalRolls = 0;
   
    for (trial = 0; trial < TRIALS; ++trial) {
        rolls = 0;
        do {
            die1 = rand() % 6 + 1;
            die2 = rand() % 6 + 1;
            ++rolls;
        } while (die1 != die2);
        totalRolls += rolls;
    }
    return (double)totalRolls / TRIALS;
}

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It looks like you mean this:

Code:

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    count = 0;
    while (1) {  // or for(;;)
        printf("Time? ");
        scanf("%f", &points[count].time);
        if ((points[count].time == 0)
            break;
        printf("Accel? ");
        scanf("%f", &points[count].accel);   
        ++count;
    }

---

Ok... now I feel really dense. I see that I forgot to change my parameter from i to count.

I am not familiar with your way of doing the while loop, but I like it. I guess the break kicks me out of the loop because of the condition met in the If statement.

Thank you so much. I feel better knowing that I was almost there and my pointers and structure wasn't the issue.