DSA Tutorial

📊 Array Implementation in DSA (Using C)

An Array is a collection of elements that are stored in contiguous memory locations. Arrays allow for the storage of multiple elements of the same type and are used widely in data structures and algorithms. Arrays provide fast access to elements through indices, making them an essential data structure in programming.

🧠 What is an Array?

An Array is a data structure that can store multiple values of the same type under a single variable name. Each element in the array is identified by its index. Arrays are particularly useful when we need to store a collection of elements and need efficient access by index.

Key Features of Arrays:

• Stores multiple elements of the same type.
• Supports fast access to elements using indices.
• Has fixed size (in static arrays) once declared.
• Elements are stored in contiguous memory locations.

💻 C Code: Basic Array Operations

#include <stdio.h>

#define MAX 5

void display(int arr[], int n) {
    for (int i = 0; i < n; i++) {
        printf("Element %d: %d\\n", i+1, arr[i]);
    }
}

int main() {
    int arr[MAX] = {10, 20, 30, 40, 50};
    
    printf("Array Elements: \\n");
    display(arr, MAX);

    printf("\\nAccessing Element at index 2: %d\\n", arr[2]);

    // Inserting new element (replacing index 3 value)
    arr[3] = 100;
    printf("Updated Array: \\n");
    display(arr, MAX);
    
    return 0;
}
  

📤 Sample Output

Array Elements: 
Element 1: 10
Element 2: 20
Element 3: 30
Element 4: 40
Element 5: 50

Accessing Element at index 2: 30
Updated Array: 
Element 1: 10
Element 2: 20
Element 3: 30
Element 4: 100
Element 5: 50
  

🔄 Operations on Arrays

Arrays can perform several common operations such as insertion, deletion, and searching. Here are some common operations:

• Insertion: Insert an element at a specific index.
• Deletion: Remove an element from a specific index.
• Searching: Find the index of an element in the array.
• Traversal: Loop through all elements of the array.

📜 Insertion Example:

void insert(int arr[], int n, int index, int value) {
    for (int i = n; i > index; i--) {
        arr[i] = arr[i - 1];
    }
    arr[index] = value;
}

int main() {
    int arr[MAX] = {10, 20, 30, 40, 50};
    int n = 5;

    printf("Before Insertion: \\n");
    display(arr, n);

    // Inserting element at index 2
    insert(arr, n, 2, 100);
    n++;

    printf("After Insertion: \\n");
    display(arr, n);
}
  

📜 Deletion Example:

void delete(int arr[], int n, int index) {
    for (int i = index; i < n - 1; i++) {
        arr[i] = arr[i + 1];
    }
    arr[n - 1] = 0; // Reset last element
}

int main() {
    int arr[MAX] = {10, 20, 30, 40, 50};
    int n = 5;

    printf("Before Deletion: \\n");
    display(arr, n);

    // Deleting element at index 3
    delete(arr, n, 3);
    n--;

    printf("After Deletion: \\n");
    display(arr, n);
}
  

🌐 Real-Life Applications of Arrays

• Implementing static lists, stacks, and queues.
• Representing matrices for mathematical computations.
• In searching algorithms like binary search.
• In databases to represent records in memory.