/* File: recovery.c (rec.c)
  * By: connoryk
  * Team: JKC
  * Date: 4/18/18
  */

 /* A file producing the correct output for problem 3c and d on the midterm */

#include <stdio.h>

int main() {

    /* Initialize variables */
    int   flag = 0;
    float distance = 0,
          prev_dist = 0,
          speed = 0,
          prev_speed = 0,
          spd_diff = 0;

printf("debug: program start\n");

    /* Get first distance */
    scanf("%f", &distance);

    /* Check if Zero*/
    while(distance == 0) {

        scanf("%f", &distance);
    }

    /* While there are more distances */
    while(flag != EOF) {

        /* Cache distance */
        prev_dist = distance;

        /* Get next distance */
        flag = scanf("%f",&distance);

        /* in the case of zero */
        if(distance == 0) {

            /* Get the indicator to cross or not cross */
            if(speed > 0) {

                printf("Car: speed is %.2f MPH; ", speed);

                /* Compute speed difference */
                spd_diff = prev_speed - speed;

                /* Set conditions for speed difference */
                if(spd_diff > 0 && speed <= 10) {

                    /* Safe to cross*/
                    printf("Safe to cross \n");
                }

	            else if(spd_diff < 0 || speed > 10) {
                    printf("DO NOT STEP OFF THE CURB! \n");
                }

                /* Update speeds */
                prev_speed = speed = 0;

                /* Update distances */
                prev_dist = distance = 0;

                /* Get next distance */
                scanf("%f",&prev_dist);

                /* Check if Zero*/
                while(prev_dist == 0){
                    scanf("%f", &prev_dist);
                }
            }
        }

        /* Common Case */
        else if(distance != 0) {

        /* Update previous speed */
        prev_speed = speed;

        /* Compute Speed */
        speed = ((prev_dist - distance) / 5280) * 3600;
        }
    }
}