#include <stdio.h>
#include <math.h>
#include <stdlib.h>
typedef struct tacka { int x;
                       int y;
    }ttacka;
        struct tacke{ struct tacka inf;
                      struct tacke *sledeci;
    }ttacke;
void prikazizfajla(FILE *f){ rewind(f);
     int d,d1;
     while((fscanf(f,"%d",&d)==1)&&(fscanf(f,"%d",&d1)==1)){
     printf("x:%d, y:%d",d,d1);
     }
}
void prikaz(struct tacke *a) {
    struct tacke *temp;
    temp=a;
    while(temp!=NULL) { printf("x:%d, y:%d\n", temp->inf.x,temp->inf.y);
                        temp=temp->sledeci;}
    }
struct tacke* unosustr(struct tacke *b, struct tacka a){ struct tacke *c;
                           c=(struct tacke *)malloc(sizeof(struct tacke));
                           c->inf=a;
                           c->sledeci=b;
                           return c;
    }
struct tacka najbliza(struct tacke *b, struct tacka a){
    if (b!=NULL){
    struct tacke *temp;
    struct tacka x1;
    x1=b->inf;
    temp=b;
    double min;
    min=sqrt((a.x-x1.x)*(a.x-x1.x)+(a.y-x1.y)*(a.y-x1.y));
    while (temp!=NULL){ if (sqrt((a.x-temp->inf.x)*(a.x-temp->inf.x)+(a.y-temp->inf.y)*(a.y-temp->inf.y))<min)
     {min=sqrt((a.x-temp->inf.x)*(a.x-temp->inf.x)+(a.y-temp->inf.y)*(a.y-temp->inf.y));
        x1=temp->inf;}
        temp=temp->sledeci;
        }
    return x1;}
    else return a;
    }
int main(){
    int d,d1,c;
    FILE *f;
    struct tacke *a,*b,*g;
    struct tacka s,k;
    f=fopen("tacke.txt","r+");
    if ((fscanf(f,"%d",&d)==1)&&(fscanf(f,"%d",&d1)==1)) { a=(struct tacke*)malloc(sizeof(struct tacke));
                                                  a->inf.x=d;
                                                  a->inf.y=d1;}
    g=a;
    b=g;
    while((fscanf(f,"%d",&d)==1)&&(fscanf(f,"%d",&d1)==1)){ a=(struct tacke*)malloc(sizeof(struct tacke));
                                                  b->sledeci=a;
                                                  a->inf.x=d;
                                                  a->inf.y=d1;
                                                  b=a; };
                                                  a->sledeci=NULL;
     while (c!=4){
     printf("za unos:1, za priaz:2,za najblizu:3, za kraj:4\n");
     scanf("%d",&c);
     switch (c){
     case 1: { printf("unesi x\n");
               scanf("%d", &s.x);
               printf("unesi y\n");
               scanf("%d", &s.y);
               g=unosustr(g,s);
               break;
         }
     case 2: { prikaz(g);
               break;
         }
     case 3: { printf("unesi x\n");
               scanf("%d", &s.x);
               printf("unesi y\n");
               scanf("%d", &s.y);
               k=najbliza(g,s);
               printf("x:%d, y:%d\n", k.x,k.y);
               break;
         }
     case 4: break;
     default: {printf("ponovo\n");
              break;
     }

    }
    }
    fclose(f);
    return 0;
    }