// CS 2SC3 / SE 2S03 solution for assignment 6 -- Pouya Larjani
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include "prog6.h"
vector error_vector = {0.0/0.0, 0.0/0.0};
node g(node n, int i) { return (n&&i>0)?g(n->next,i-1):n; }
double vec_mag(vector v) { return sqrt(v.x*v.x+v.y*v.y); }
vec_store make_vec_store() { return calloc(1,sizeof(struct vs)); }
vector get_vec(vec_store s, int i) {
    if (!s || i<0 || i>=s->size) {
        fprintf(stderr, "Index out of bounds.\n"); return error_vector; }
    else return g(s->seq, i)->data; }
void delete_vec(vec_store s, int i) {
    if (!s || i<0 || i>=s->size) {
        fprintf(stderr, "Index out of bounds.\n"); return; }
    node p = g(s->seq, i-1);
    if (i) { node n=p; p = p->next; n->next = p->next; } else s->seq = p->next;
    free(p); s->size--;}
void insert_vec(vec_store s, vector v) {
    node n = (node)malloc(sizeof(struct node_record)); double m = vec_mag(v);
    n->data = v; n->next = s->seq; s->size++;
    for (node p=n; p; p=p->next)
        if (!p->next || vec_mag(p->next->data) > m) {
            n->next = p->next; if (p==n) s->seq = n; else p->next = n; break;}}
void print_vec_store(vec_store s) {
    printf("vec_store[%d] = {", s->size);
    for (node n=s->seq; n; n=n->next)
        printf("(%f,%f)%s", n->data.x, n->data.y, n->next?", ":"}\n"); }