C: Enter coordinate and get out a quadrant

[gnozahs]

The task is to create a c source code program that will name a quadrant when a given coordinate is given.
Example:
Input Coordinate Pair: 0 5.3
Positive y Axis

I need help on how to start this. I know I have to use if else statements but I'm not sure how to work those. I was wondering if someone could help me start off? Thanks.

[tabstop]

So how do you, yourself, know that (0,5.3) is on the positive y-axis? What is true about all the points on the positive y-axis?

Ditto for all the quadrants: what has to be true about (x,y) for the point to be in (say) quadrant III?

[gnozahs]

Alright, so this is what I came up with so far.

But I'm getting an error:invalid lvalue in assignment on line 20 and 22. Am I doing the else if statements wrong?

/* Directives */

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

int main(void)

{

int x, y;

printf("Enter coordinate pair: ");
scanf("%d %d", &x, &y);
if (x = 0 && y > 0)
printf("Positive y Axis");
else if (x > 0 && y = 0)
printf("Positive x Axis");
else if (x < 0 && y = 0)
printf("Negative x Axis");
else if (x = 0 && y < 0)
printf("Negative y Axis");


/* End Program */
return(0);
}

[tabstop]

There's a difference between = and ==.

[gnozahs]

Oh! Missed that definition. Thanks!

[gnozahs]

Wait, even though I'm getting the right answers from the program, the grader program is telling me it's not 100% correct. Is there a way I could rewrite the if statements to have the "if else" statements? I'm thinking it's looking for the "if else" statements.

[tabstop]

Is the grader program looking at your source code, or just your output? (If the latter, then it doesn't matter whether you use else if; but also, it's probably using input that it may not be telling you about -- in other words, just because it works on your one or two sample inputs doesn't mean it actually works.)

[gnozahs]

Ok, so I changed all the other previous "if"except the first "if to "else if" and the int x, y to float x, y since the grader program said it wanted x and y to be float.

The grader program finally accepted it. Thanks!!!

[nonoob]

I wouldn't have passed you. You haven't identified the quadrant. That is, if neither coordinate is zero??? Where does the program go if both are zero?