hw4.c

Computes the length of a line using two (x,y) points. Uses pointers

/*************************************************************
needed files, Lines.c and Lines.h. This is able to	*
*take in 4 values and set them to points using pointers then 	*
*uses a memory allocation to print them off in the reverse	*
*order they were entered while you claculate the distance	*
*between the points						*
****************************************************************/	


#include "Lines.h"	//You call it like this becasue it contains function prototypes.
#include <stdio.h>
#include<stdlib.h>


void printLineSegment(struct line*, int);	

int main(int argc, char* argv[])
{
	
	int size = atoi(argv[1]);	//transfoirms the input from a string to an integer

	struct line * line_arr;		

	line_arr = (struct line*)malloc(size+1);	//set up an allocated memory spot to perform all of the tasks at hand and store the values to be input 
	int i;

	for(i = 0; i<size; i++)		//given the argument input decrememnt the size until it = 0
	{
		printf("Enter x1 y1 x2 y2:\n");
		scanf("%lf %lf %lf %lf",&line_arr[i].p1.x,&line_arr[i].p1.y,&line_arr[i].p2.x,&line_arr[i].p2.y);	//scan in the numbers as long floating points
								// then store them in in memory adresses that are allocated my the line array
	}

	printLineSegment(line_arr, size);	//go to printLineSegment using the size of the array

	return 0;
}

void printLineSegment(struct line* lines,int size)
{
	int i;
	double dist = 0;	//just initialize the distance to be 0
	
	for(i = (size-1); i>=0 ; i--)	//make sure you start printing the line at value 1 - the argument to ensure they all are admitted
	{
		
		dist = length_line(&lines[i]);	//call the distance from the Lines.c code
		printf("Line: %.2f,%.2f %.2f,%.2f dist: %.2f\n", lines[i].p1.x, lines[i].p1.y, lines[i].p2.x, lines[i].p2.y, dist);
		//print off the values as inputs that are seperated by a space and do not read in leading 0's and what not.
		//That was taken care of in the scan function becasue they were stored approrpiatly.
		//This for loop is going to print off the lines in the reverse order that they were entered.
		
	}
}