activitati student deadline greedy

#include <stdio.h>
#include <stdlib.h>

struct interval
{
    int id, time, deadline;
};

void citire(FILE *fin,int *n, struct interval *ptr)
{
    fscanf(fin,"%d",&(*n));
    int i;

    for (i=0; i<*n; i++)
    {
        fscanf(fin,"%d %d",&ptr->time,&ptr->deadline);
        ptr->id = i + 1;
        ptr++;
    }

}

void afisare(FILE *fout, int n, struct interval *ptr)
{
    fprintf(fout,"Vector sortat crescator dupa deadline:\n");

    int i;

    fprintf(fout,"%d\n",n);

    for (i=0; i<n; i++)
    {
        fprintf(fout,"id %d: %d %d \n", ptr->id, ptr->time, ptr->deadline);
        ptr++;
    }

}

void sortare(int n, struct interval *v) //sortare cu complexitate n^2
{
    int i,j;
    struct interval aux;

    for (i=0; i<n; i++)
        for (j=i+1; j<n; j++)
            if (v[i].deadline > v[j].deadline)
                {
                    aux = v[i];
                    v[i] = v[j];
                    v[j] = aux;
                }

}

int comparator(const void *s1, const void *s2) //asta e pentru quicksort
{
    struct interval *e1 = (struct interval *) s1;
    struct interval *e2 = (struct interval *) s2;

    //return e1->deadline - e2->deadline;

    if (e1->deadline > e2->deadline)
        return 1;
    else if (e1->deadline < e2->deadline)
        return -1;
    else
        return e1->time - e2->time;

    return 0;
}

void greedy(FILE *fout, int n, struct interval *v)
{
    fprintf(fout,"\n********************************************************\nRezolvare:\n");

    int i, lb = 0, hb, delay;

    for (i=0; i<n; i++)
    {
        hb = lb + v[i].time;

        fprintf(fout,"activitatea %d in intervalul [%d,%d) - intarziere %d\n",v[i].id, lb, hb, hb - v[i].deadline);

        lb = lb + v[i].time;
    }

}

int main()
{
    FILE *fin, *fout;

    fin = fopen("date.in","r");
    fout = fopen("date.out","w");

    struct interval vec[100];
    int n;

    citire(fin,&n,vec);
    qsort(vec,n,sizeof(struct interval),comparator);
    afisare(fout,n,vec);
    greedy(fout,n,vec);

    return 0;
}