Лаб5/6

main.c

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

// d)
char* getAlphabet() {
    char* pAlp = malloc(26); //Выделение памяти
    if (pAlp == NULL) {
        printf("Cannot allocate memory");
        return NULL;
    }
    int i = 0;
    for (unsigned int sym = 'a'; sym <= 'z'; sym++) {
        pAlp[i] = (char) sym;
        i++;
    }
    char* tmp = realloc(pAlp, 53); //Расширение памяти
    if (tmp == NULL)
        printf("Cannot allocate memory");
        return NULL;
    pAlp = tmp;
    for (unsigned int sym = 'Z'; sym >= 'A'; sym--) {
        pAlp[i] = (char) sym;
        i++;
    }
    pAlp[i] = '\0';
    return pAlp;
}

// e)
void printString(const char* pString) {
    while (*pString != '\0') {
        putchar(*pString);
        pString++;
    }
}

// f) Вывод символов из строки от start до end включая
void alphabetSubstr(const char* pString, char start, char end) {
    const char* ptr = strchr(pString, start);
    while (*ptr != end) {
        putchar(*ptr);
        ptr++;
    }
    putchar(*ptr);
    putchar('\n');
}

// i) Сравнение памяти, собственная реализация
int memecmp(const void* str1, const void* str2, size_t n) {
    const char* s1 = str1;
    const char* s2 = str2;
    while (n > 0) {
        if (*s1 != *s2) {
            if (*s1 > *s2) return 1;
            if (*s2 > *s1) return -1;
        }
        s1++;
        s2++;
        n--;
    }
    return 0;
}

int main() {
    // a) Объявление и присваивание переменных
    int Int = 1;
    char Char = 'z';
    double Double = 1.1;
    // b) Объявление и присваивание указателей
    int* pInt = &Int;
    char* pChar = &Char;
    double* pDouble = &Double;
    // c) Вывод разнообразной информации о переменных и указателях
    printf("----------------------------------------------\n");
    printf("Address of int = %p\n", pInt);
    printf("Value of pointer to int = %d\n", *pInt);
    printf("Address of pointer to int = %p\n", &pInt);
    printf("Value of int = %d\n", Int);
    printf("Size of int = %llu\n", sizeof(Int));
    printf("Size of pointer to int = %llu\n", sizeof(pInt));
    printf("----------------------------------------------\n");
    printf("Address of char = %p\n", pChar);
    printf("Value of pointer to char = %c\n", *pChar);
    printf("Address of pointer to char = %p\n", &pChar);
    printf("Value of char = %c\n", Char);
    printf("Size of char = %llu\n", sizeof(Char));
    printf("Size of pointer to char = %llu\n", sizeof(pChar));
    printf("----------------------------------------------\n");
    printf("Address of double = %p\n", pDouble);
    printf("Value of pointer to double = %f\n", *pDouble);
    printf("Address of pointer to double = %p\n", &pDouble);
    printf("Value of double = %f\n", Double);
    printf("Size of double = %llu\n", sizeof(Double));
    printf("Size of pointer to double = %llu\n", sizeof(pDouble));
    printf("----------------------------------------------\n");
    // g) Вывоз функций из main()
    const char* pStr = getAlphabet();
    printf("%s\n", pStr);
    printString("example\n");
    alphabetSubstr(pStr, 's', 'E');
    free(pStr); //Освобождение памяти
    // h) Чтение и вывод строки
    int strSz;
    scanf_s("%d", &strSz);
    char* pH = malloc((size_t)strSz + 1);
    if (pH != NULL) { //Проверка выделения памяти
        char* pStart = pH;
        scanf_s("%s", pH, strSz + 1);
        for (; *pH != '\0'; pH++) {
            putchar(*pH);
        }
        pH = pStart;
        free(pH);
        putchar('\n');
    }
    else {
        printf("Cannot allocate memory");
    }
    // j) Сравнение результатов собственной и стандртной реализации функции memcmp
    const char* pStr1 = "ABC";
    const char* pStr2 = "AbC";
    printf("Strings are equal (my func) vs (std func): %d vs %d\n",
        memecmp(pStr1, pStr1, 3),
        memcmp(pStr1, pStr1, 3));
    printf("String 2 is greater than String 1 (my func) vs (std func): %d vs %d\n",
        memecmp(pStr1, pStr2, 3),
        memcmp(pStr1, pStr2, 3));
    printf("String 1 is greater than String 2 (my func) vs (std func): %d vs %d\n",
        memecmp(pStr2, pStr1, 3),
        memcmp(pStr2, pStr1, 3));
    return 0;
}