TheAlgorithms-C/misc/cartesian_To_Polar.c

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

const double pi = 3.141592653589793238462643383279502884;

/**
give as arguments to the executable two x and y coordinates
outputs a polar coordinate
**/
int main() {
    double x, y;
    double r, theta, thetaFinal;
    scanf("%lf %lf", &x, &y);
    r = hypot(x, y);
	if (x != 0) {
		if (y != 0) {
			theta = atan(y / x);
			if ((x > 0 && y > 0) || (x == -y)) { //Q1
				thetaFinal = theta;
			} else if (x < 0 && y > 0) { //Q2
				thetaFinal = theta + pi;
			} else if (x < 0 && y < 0) { //Q3
				thetaFinal = theta - pi;
			} else if (x > 0 && y < 0) { //Q4
				thetaFinal = 2 * pi - theta;
			}
		}
	}
	if (x == 0) { //exceptions when no actual angle is present
		if (y > 0) {
			thetaFinal = pi / 2;
		} else {
			thetaFinal = -(pi / 2);
		}
	}
	if (y == 0) {
		if (x > 0) {
			thetaFinal = 0;
		} else {
			thetaFinal = -pi;
		}
	}
	printf("%.2f %.2f\n", r, atan2(y, x));
}