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

struct point
{
    float x;
    float y;
};

void point_move(struct point* p, float x, float y)
{
    p->x += x;
    p->y += y;
}

float point_abs(const struct point* p)
{
    return sqrtf(p->x*p->x + p->y*p->y);
}

int main(void)
{
    struct point p;
    printf("point (%f,%f)\n", p.x, p.y);
    printf("abs %f\n", point_abs(&p));
    return 0;
}