find circle from to points and radius

findCirc.c

#include <stdio.h> // NULL, 
#include <math.h> 

typedef struct Point {
    float x;
    float y;
} point;

typedef struct Circle {
    point c;
    float r;
} circle;

typedef struct Circles {
    circle* C;
    unsigned int n;
} circles;

// typedef enum Cases {A, B, C} cases;

int signnum(double x) {
    if (x > 0.0) return 1;
    if (x < 0.0) return -1;
    return 0;
}

// Cases detect(Point p1, Point p2, float r) {
//     int tmpSign = signnum(4 * pow(r, 2) - pow((p1.x - p2.x), 2) - pow((p1.y - p2.y), 2));
//     switch(tmpSign) {
//         case -1 :
//             return A;
//             break;
//         case 0 :
//             return B;
//             break;
//         case 1 :
//             return C;
//     }
// }


Circles findCircle(Point p1, Point p2, float r) {
    int tmpSign = signnum(4 * pow(r, 2) - pow((p1.x - p2.x), 2) - pow((p1.y - p2.y), 2));
    circles tmpCircles;
    switch(tmpSign) {
        case -1 :
            tmpCircles.n = 0;
            tmpCircles.C = NULL;
            break;
        case 0 :
            tmpCircles.n = 1;
            circle tmpCircle = {};
            break;
        case 1 :
            break;
    }
    return tmpCircles;
}



int main() {
   return 0;
}