punti.c

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

typedef struct {
    int x, y;
} Point;

struct el {
    struct el *prev;
    struct el *next;
    Point *p;

}
typedef struct el *list;

// uso di una sentinella
void insert(list set, Point *p) {
    list last = set->prev;
    list item = (list) malloc(sizeof(struct el));
    item->p = p;
    for (; temp->p != NULL; temp = temp->prev) {
        if (p->x > temp->x || (p->x == temp->x && p->y >= temp->y)) {
            break;
        }
    }
    item->prev = temp;
    item->next = temp->next;
    temp->next->prev = item;
    temp->next = item;
}

int distanza(Point *a, Point *b) {
    return sqrt(pow(b->x - a->x, 2)+pow(b->y - a->y, 2))
}

void elimina(list set, Point *p, int d) {
    list temp = set->next;
    list x;
    for (; temp->p != NULL; temp = temp->next) {
        if (distanza(temp->p, p) < d) {
            temp->prev->next = temp->next;
            temp->next->prev = temp->prev;
            x = temp;
            temp = temp->prev;
            free(x);
        }
    }
}