Gestione file/1/2.txt

+aaabca

Gestione file/1/main.c

+#include <stdio.h>
+
+#include <errno.h>
+#include <string.h>
+#define err(s) fprintf(stderr, s "%s\n", strerror(errno))
+
+#define F1_STR "1.txt"
+#define F2_STR "2.txt"
+
+int main(void) {
+    int ret = 0;
+    FILE *f1;
+    if ((f1 = fopen(F1_STR, "r"))) {
+
+        FILE *f2;
+        if ((f2 = fopen(F2_STR, "r"))) {
+
+            char c1;
+            char c2;
+            int diff = 0;
+            while (fscanf(f1, "%c", &c1) != EOF &&
+                   fscanf(f2, "%c", &c2) != EOF &&
+                   !diff) {
+                if (c1 != c2) {
+                    diff = 1;
+                    printf("file 1: %c, file2: %c\n", c1, c2);
+                }
+            }
+            
+            fclose(f2);
+
+        } else {
+            ret = 1;
+            err(F2_STR ": ");
+        }
+
+        fclose(f1);
+    } else {
+        ret = 1;
+        err(F1_STR ": ");
+    }
+
+    return ret;
+}

Gestione file/2/1.txt

+abcdefghijk

Gestione file/2/2.txt

+abbdefgjklk

Gestione file/2/main.c

+#include <stdio.h>
+
+#include <errno.h>
+#include <string.h>
+#define err(s) fprintf(stderr, s "%s\n", strerror(errno))
+
+#define F1_STR "1.txt"
+#define F2_STR "2.txt"
+#define FOUT_STR "out.txt"
+
+int main(void) {
+    int ret = 0;
+    FILE *f1;
+    if ((f1 = fopen(F1_STR, "r"))) {
+
+        FILE *f2;
+        if ((f2 = fopen(F2_STR, "r"))) {
+
+            FILE *fout;
+            if ((fout = fopen(FOUT_STR, "w"))) {
+
+                char c1;
+                char c2;
+                while (fscanf(f1, "%c", &c1) != EOF &&
+                       fscanf(f2, "%c", &c2) != EOF) {
+                    if (c1 != c2) {
+                        printf("file 1: %c, file2: %c\n", c1, c2);
+                        fprintf(fout, "%c%c\n", c1, c2);
+                    }
+                }
+                fclose(fout);
+
+            } else {
+                ret = 1;
+                err(FOUT_STR ": ");
+            }
+            fclose(f2);
+        } else {
+            ret = 1;
+            err(F2_STR ": ");
+        }
+        fclose(f1);
+    } else {
+        ret = 1;
+        err(F1_STR ": ");
+    }
+
+    return ret;
+}

Gestione file/2/out.txt

+cb
+hj
+ik
+jl

Gestione file/3/1.txt

+aaa bbb ccc ddd eee

Gestione file/3/2.txt

+aaa b ccc dd eeee

Gestione file/3/main.c

+#include <stdio.h>
+
+#include <errno.h>
+#include <string.h>
+#define err(s) fprintf(stderr, s "%s\n", strerror(errno))
+
+#define F1_STR "1.txt"
+#define F2_STR "2.txt"
+
+int main(void) {
+    int ret = 0;
+    FILE *f1;
+    if ((f1 = fopen(F1_STR, "r"))) {
+
+        FILE *f2;
+        if ((f2 = fopen(F2_STR, "r"))) {
+
+            char s1[128];
+            char s2[128];
+            while (fscanf(f1, "%s", s1) != EOF &&
+                   fscanf(f2, "%s", s2) != EOF) {
+                if (strcmp(s1, s2) != 0) {
+                    puts(s2);
+                }
+            }
+
+            fclose(f2);
+        } else {
+            ret = 1;
+            err(F2_STR ": ");
+        }
+        fclose(f1);
+    } else {
+        ret = 1;
+        err(F1_STR ": ");
+    }
+
+    return ret;
+}

Le stringhe in C/1.c

+#include <stdio.h>
+
+size_t slen(char *s) {
+    size_t i = 0;
+    while (s[i] != '\0') { ++i; }
+    return i;
+}
+
+void strrev(char *src, char *dst) {
+    size_t len = slen(src);
+    for (size_t i = 0; i < len; ++i) {
+        dst[i] = src[len - 1 - i];
+    }
+    src[len] = '\0';
+}
+
+int main(void) {
+    char s[] = "Informatica";
+    char s_rev[sizeof(s)];
+
+    strrev(s, s_rev);
+    printf("%s", s_rev);
+}

Le stringhe in C/2.c

+size_t lunghezza(char *s) {
+    size_t i = 0;
+    while (s[i] != '\0') { ++i; }
+    return i;
+}
+
+int palindroma(char *s) {
+    int is_palindrome = 1;
+    size_t len = lunghezza(s);
+    for (size_t i = 0; i < len / 2 && is_palindrome; ++i) {
+        if (s[i] != s[len - 1 - i]) { is_palindrome = 0; }
+    }
+    return is_palindrome;
+}
+
+void cswap(char *c1, char *c2) {
+    char temp = *c1;
+    *c1 = *c2;
+    *c2 = temp;
+}
+
+void inverti(char *s) {
+    size_t len = lunghezza(s);
+    for (size_t i = 0; i < len / 2; ++i) {
+        cswap(&s[i], &s[len - 1 - i]);
+    }
+}

Lezione 3/1.c

+#include <stdio.h>
+
+void print_repeat_char(char c, unsigned n) {
+    for (unsigned i = 0; i < n; ++i) {
+        printf("%c", c);
+    }
+}
+
+int main(void) {
+    puts("Lato del quadrato");
+    unsigned side;
+    scanf("%u", &side);
+
+    for (unsigned row = 1; row <= side; ++row) {
+        unsigned stars_amount = row;
+        print_repeat_char('*', stars_amount);
+
+        unsigned plus_amount = side - stars_amount;
+        print_repeat_char('+', plus_amount);
+
+        puts("");
+    }
+
+    return 0;
+}

Lezione 3/2.c

+#include <stdio.h>
+#include <stdbool.h>
+#include <assert.h>
+
+#define END -1000
+
+#define ASC_STR "crescente"
+#define DESC_STR "decrescente"
+#define NEITHER_STR "ne' " ASC_STR "ne' " DESC_STR
+
+const char *sequence_monotony_str(bool asc, bool desc) {
+    const char *sequence_kind_str;
+    printf("la sequenza e' ");
+    if (asc) {
+        assert(!desc);
+        sequence_kind_str = ASC_STR;
+    } else if (desc) {
+        assert(!asc);
+        sequence_kind_str = DESC_STR;
+    } else {
+        sequence_kind_str = NEITHER_STR;
+    }
+    return sequence_kind_str;
+}
+
+int main(void) {
+    int sum = 0;
+    int prev, num;
+    bool asc = true, desc = true;
+    unsigned num_counter = 0;
+
+    scanf("%d", &prev);
+    sum += prev;
+
+    if (prev != END) {
+        num_counter = 1;
+        while (scanf("%d", &num), num != END) {
+            ++num_counter;
+            sum += num;
+            asc &= num > prev;
+            desc &= num < prev;
+
+            prev = num;
+        }
+    }
+
+
+    if (num_counter > 1) {
+        puts(sequence_monotony_str(asc, desc));
+    } else {
+        puts("la sequenza non e' abbastanza lunga per essere definita crescente o decrescente");
+    }
+    
+    printf("somma: %d\n", sum);
+
+    return 0;
+}

Lezione 4/1.c

+#include <stdio.h>
+#include <assert.h>
+#include <stdbool.h>
+
+# define LEN(x) (sizeof(x) / sizeof(*x))
+
+enum Product { COFFE = 0, TEA = 1, CHOCOLATE = 2, CAPPUCCINO = 3, LAST_PRODUCT };
+const char *const products_str[] = { "caffe'", "the", "cioccolata", "cappuccino", };
+const int products_price[] = { 50, 40, 60, 70 };
+
+const int coins[] = { 1, 5, 10, 20, 50 };
+
+void print_numbered_strings(const char *const products[], size_t len) {
+    for (size_t i = 0; i < len; ++i) {
+        printf("%zu. %s\n", i, products[i]) ;
+    }
+}
+
+int input_int() {
+    int ret;
+    scanf("%d", &ret);
+    return ret;
+}
+
+int input_int_range(int lower, int upper) {
+    int ret;
+    while ((ret = input_int()) < lower || ret > upper) {
+        puts("Valore non ammesso");
+    }
+    return ret;
+}
+
+bool is_in_array(int needle, const int haystack[], size_t len) {
+    bool found = false;
+    // could use memmem(3) instead
+    for (size_t i = 0; i < len && !found; i++) {
+        if (haystack[i] == needle) { found = true; }
+    }
+    return found;
+}
+
+int input_int_filter(const int whitelist[], size_t len) {
+    int ret;
+    while (ret = input_int(), !is_in_array(ret, whitelist, len)) {
+        puts("Valore non ammesso");
+    }
+    return ret;
+}
+
+void calculate_change(int total, int *count_5, int *count_1) {
+    *count_5 = total / 5;
+    total -= 5 * *count_change;
+
+    *count_1 = total;
+}
+
+int main(void) {
+    assert(LEN(products_str) == LEN(products_price));
+    assert(LEN(products_str) == LAST_PRODUCT);
+
+    int selected_product;
+    int credit = 0;
+    int inserted_coin;
+    int count_change_5 = 0, count_change_1 = 0;
+
+    puts("Seleziona il prodotto");
+    print_numbered_strings(products_str, LEN(products_str));
+    selected_product = input_int_range(0, LAST_PRODUCT);
+
+    printf("Costo: %d centesimi\n", products_price[selected_product]);
+
+    puts("Inserisci monete");
+    while (credit < products_price[selected_product]) {
+        inserted_coin = input_int_filter(coins, LEN(coins));
+        credit += inserted_coin;
+    }
+
+    calculate_change(
+            credit - products_price[selected_product],
+            &count_change_5, &count_change_1
+    );
+
+    printf("Resto: %d monete da 5, %d monete da 1\n", count_change_5, count_change_1);
+
+    return 0;
+}

Lezione 4/2.c

+#include <stdio.h>
+#include <math.h>
+
+#define PERC_CRASHED (+0.12)
+#define PERC_NOT_CRASHED (-0.04)
+
+int main(void) {
+    double new_total_amount = 0;
+    double old_total_amount = 0;
+    do {
+        puts("Inserire numero di auto");
+        unsigned int n_cars;
+        scanf("%u", &n_cars);
+
+        double old_client_amount = 0;
+        double new_client_amount = 0;
+        for (unsigned int i = 0; i < n_cars; i++) {
+            double old_car_amount;
+            double new_car_amount;
+
+            printf("Inserire importo dell'auto %u\n", i + 1);
+            do {
+                scanf("%lf", &old_car_amount);
+            } while (old_car_amount < 0);
+
+            old_client_amount += old_car_amount;
+
+            puts("Inserire numero di incidenti dell'anno scorso");
+            int n_crashes;
+            do {
+                scanf("%u", &n_crashes);
+            } while (n_crashes < 0);
+
+            if (n_crashes > 0) {
+                new_car_amount = old_car_amount + PERC_CRASHED * old_car_amount;
+            } else {
+                new_car_amount = old_car_amount - PERC_NOT_CRASHED * old_car_amount;
+            }
+
+            new_client_amount += new_car_amount;
+        }
+        printf("Importo da pagare per il cliente: %lf\n", new_client_amount);
+
+        old_total_amount += old_client_amount;
+        new_total_amount += new_client_amount;
+
+        puts("Inserire nuovo cliente? y/n");
+    } while (getchar() == 'y');
+
+    printf("Totale degli importi: %lf, variazione rispetto al precedente: %lf\n",
+            new_total_amount, fabs(new_total_amount - old_total_amount));
+}