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Q1: Create a pointer variable, assign it the address of an integer, and print the value at that address.

output.cpp

// C code
#include <stdio.h>

int main() {
    int num = 42; // An integer variable
    int *ptr;     // Declare a pointer to an integer

    ptr = &num;   // Assign the address of 'num' to the pointer

    printf("Value at the address pointed to by the pointer: %d\n", *ptr);

    return 0;
}

Q2: Swap the values of two variables using pointers.

Q3: Allocate memory for an integer using malloc function, assign a value, and then free the memory.

output.cpp

// C code
#include <stdio.h>
#include <stdlib.h>

int main() {
    int *numPtr; // Declare a pointer to an integer

    // Allocate memory for an integer
    numPtr = (int *)malloc(sizeof(int));

    if (numPtr == NULL) {
        printf("Memory allocation failed.\n");
        return 1;
    }

    // Assign a value to the allocated memory
    *numPtr = 42;

    printf("Value stored in allocated memory: %d\n", *numPtr);

    // Free the allocated memory
    free(numPtr);

    return 0;
}

Q4: Implement a dynamic array using malloc or new, add elements, and resize the array as needed.

output.cpp

// C code
#include <stdio.h>
#include <stdlib.h>

typedef struct DynamicArray {
    int *data;
    size_t size;
    size_t capacity;
} DynamicArray;

void initDynamicArray(DynamicArray *arr, size_t initialCapacity) {
    arr->data = (int *)malloc(initialCapacity * sizeof(int));
    arr->size = 0;
    arr->capacity = initialCapacity;
}

void appendElement(DynamicArray *arr, int element) {
    if (arr->size == arr->capacity) {
        arr->capacity *= 2;
        arr->data = (int *)realloc(arr->data, arr->capacity * sizeof(int));
    }
    arr->data[arr->size++] = element;
}

void freeDynamicArray(DynamicArray *arr) {
    free(arr->data);
    arr->size = 0;
    arr->capacity = 0;
}

int main() {
    DynamicArray arr;
    initDynamicArray(&arr, 2);

    for (int i = 0; i < 10; i++) {
        appendElement(&arr, i * 10);
    }

    for (size_t i = 0; i < arr.size; i++) {
        printf("Element %zu: %d\n", i, arr.data[i]);
    }

    freeDynamicArray(&arr);

    return 0;
}

Q5: Iterate through an integer array using a pointer.

output.cpp

// C code
#include <stdio.h>

int main() {
    int arr[] = {1, 2, 3, 4, 5};
    int *ptr = arr; // Initialize a pointer to the start of the array

    for (int i = 0; i < sizeof(arr) / sizeof(arr[0]); i++) {
        printf("Element %d: %d\n", i, *ptr);
        ptr++; // Move the pointer to the next element
    }

    return 0;
}

Q6: Write a function to find the length of a string (null-terminated character array) using pointers.

output.cpp

// C code
#include <stdio.h>

size_t stringLength(const char *str) {
    const char *ptr = str; // Initialize a pointer to the start of the string

    while (*ptr != '\0') {
        ptr++; // Move the pointer to the next character
    }

    return ptr - str;
}

int main() {
    const char *text = "Hello, World!";
    size_t length = stringLength(text);
    printf("Length of the string: %zu\n", length);

    return 0;
}

Q7: Given an array and a pointer to an element, find the Nth element using pointer arithmetic.

output.cpp

// C code
#include <stdio.h>

int main() {
    int arr[] = {10, 20, 30, 40, 50};
    int *ptr = arr; // Initialize a pointer to the start of the array
    int n = 2;      // Find the 3rd element (0-based index)

    // Use pointer arithmetic to find the Nth element
    int *nthElement = ptr + n;

    if (nthElement >= arr && nthElement < arr + sizeof(arr) / sizeof(arr[0])) {
        printf("Nth element: %d\n", *nthElement);
    } else {
        printf("Index out of bounds\n");
    }

    return 0;
}

Q8: Implement a function to concatenate two C-style strings.

output.cpp

// C code
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

char* concatenateStrings(const char* str1, const char* str2) {
    size_t len1 = strlen(str1);
    size_t len2 = strlen(str2);
    char* result = (char*)malloc(len1 + len2 + 1);

    if (result != NULL) {
        strcpy(result, str1);
        strcat(result, str2);
    }

    return result;
}

int main() {
    const char* string1 = "Hello, ";
    const char* string2 = "World!";
    char* concatenated = concatenateStrings(string1, string2);

    if (concatenated != NULL) {
        printf("Concatenated string: %s\n", concatenated);
        free(concatenated);
    } else {
        printf("Memory allocation failed.\n");
    }

    return 0;
}

Q9: Define a structure representing a student with name and age. Create an array of students of struct type and access their attributes. Use pointers for this purpose.

output.cpp

// C code
#include <stdio.h>

// Define the structure for a student
struct Student {
    char name[50];
    int age;
};

int main() {
    // Create an array of students
    struct Student students[3];

    // Initialize the attributes of the first student
    strcpy(students[0].name, "Alice");
    students[0].age = 20;

    // Initialize the attributes of the second student
    strcpy(students[1].name, "Bob");
    students[1].age = 22;

    // Initialize the attributes of the third student
    strcpy(students[2].name, "Charlie");
    students[2].age = 21;

    // Access and print the attributes of the students using pointers
    struct Student *ptr = students;

    for (int i = 0; i < 3; i++) {
        printf("Student %d - Name: %s, Age: %d\n", i + 1, ptr->name, ptr->age);
        ptr++;
    }

    return 0;
}

Q10: Write a function that calculates the sum and difference of two integers and returns the results through pointers.

output.cpp

// C code
#include <stdio.h>

void calculateSumAndDifference(int num1, int num2, int *sumResult, int *differenceResult) {
    *sumResult = num1 + num2;
    *differenceResult = num1 - num2;
}

int main() {
    int number1 = 10;
    int number2 = 5;
    int sum, difference;

    calculateSumAndDifference(number1, number2, &sum, &difference);

    printf("Sum: %d\n", sum);
    printf("Difference: %d\n", difference);

    return 0;
}

Q11: Implement a function to find the maximum and minimum values in an array of integers by using pointers.

output.cpp

// C code
#include <stdio.h>

void findMaxMin(const int *arr, size_t size, int *maxResult, int *minResult) {
    if (size == 0) {
        return; // Handle an empty array if necessary
    }

    *maxResult = *arr;
    *minResult = *arr;

    for (size_t i = 1; i < size; i++) {
        if (arr[i] > *maxResult) {
            *maxResult = arr[i];
        } else if (arr[i] < *minResult) {
            *minResult = arr[i];
        }
    }
}

int main() {
    int numbers[] = {10, 5, 20, 30, 15};
    size_t size = sizeof(numbers) / sizeof(numbers[0]);
    int max, min;

    findMaxMin(numbers, size, &max, &min);

    printf("Maximum value: %d\n", max);
    printf("Minimum value: %d\n", min);

    return 0;
}

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