Fondamenti di Programmazione     a.a. 2011-2012
Soluzioni prova scritta - 24 febbraio 2012

int abs(int x) { return (x > 0 ? x : -x); }

int smooth(int S[], int n, int k) {
    int max = 0;
    for (int i = 0 ; i < n ; i++) {
        for (int j = i ; j < n ; j++) {
            if (j - i + 1 > max) {
                int h = i;
                while (h < j && abs(S[h] - S[h + 1]) <= k)
                    h++;
                if (h == j) max = j - i + 1;
            }
        }
    }
    return max;
}

int lcs(char *s1, char *s2, int *start1, int *start2) {
    int max = 0;
    for (int i = 0 ; s1[i] != '\0' ; i++)
        for (int j = 0 ; s2[j] != '\0' ; j++) {
            int k = 0;
            while (s1[i + k] != '\0' && s1[i + k] == s2[j + k])
                k++;
            if (k > max) {
                max = k;
                *start1 = i;
                *start2 = j;
            }
        }
    return max;
}

#include <stdlib.h>
#include <string.h>

char *comstr(char **sA1, char **sA2, int n) {
    char *com = NULL;
    int len = 0;
    for (int i = 0 ; i < n ; i++)
        for (int j = 0 ; j < n ; j++) {
            if (strcmp(sA1[i], sA2[j]) == 0) {
                int sep = (com == NULL ? 0 : 1);
                com = realloc(com, len + sep + strlen(sA1[i]) + 1);
                if (sep == 1) {
                    com[len] = ';';
                    com[len + 1] = '\0';
                }
                strcat(com, sA1[i]);
                len += sep + strlen(sA1[i]);
                break;
            }
        }
    return com;
}

#include <stdlib.h>

PList rect(PList L, int x1, int y1, int x2, int y2, PList *out) {
    PList *pp = &L;
    if (out != NULL) *out = NULL;
    while (*pp != NULL) {
        Point *p = *pp;
        int x = p->x, y = p->y;
        if (x < x1 || x > x2 || y < y1 || y > y2) {   //se il punto è esterno al rettangolo,
            *pp = p->next;                            //sgancia il punto dalla lista
            if (out != NULL) {
                p->next = *out;
                *out = p;
            } else
                free(p);
        } else
            pp = &((*pp)->next);
    }
    return L;
}

#include <stdio.h>
#include <string.h>

int mfirst(char *fname) {
    FILE *f = fopen(fname, "r+b");
    if (f == NULL) 
        return -1;
    Rec r, rr;
    int count = 0, index = 0;
    while (fread(&r, sizeof(Rec), 1, f) == 1) {
        rewind(f);
        int isfirst = 1;
        for (int i = 0 ; i < index && isfirst ; i++) {
            fread(&rr, sizeof(Rec), 1, f);
            if (strcmp(rr.spec, r.spec) == 0) 
                isfirst = 0;
        }
        r.first = isfirst;
        if (isfirst) count++;
        fseek(f, index*sizeof(Rec), SEEK_SET);
        fwrite(&r, sizeof(Rec), 1, f);
        fflush(f);
        index++;
    }
    fclose(f);
    return count;
}

#include <stdlib.h>

List clist(List C) {
    if (C == NULL || C->next == C) //se la lista è vuota o ha un solo elemento,
        return C;                  //rimane invariata
    int max = 0;
    Elem *p = C, *pmax = NULL;
    do {
        Elem *e = p;
        int len = 1;    //determina la lunghezza della più lunga sottolista uniforme 
        while (e->count == (e->next)->count && e->next != p) {    //a partire da p
            len++;
            e = e->next;
        }
        if (len > max) {
            max = len;
            pmax = p;
        }
        p = p->next;
    } while (p != C);
    if (max >= 2) {
        pmax->count = max*(pmax->count);
        for (int i = 1 ; i < max ; i++) {
            p = pmax->next;
            pmax->next = p->next;
            free(p);
        }
    }
    return pmax;
}