🚀 DSA with C – Day 1: Introduction & Setup

 

🚀 DSA with C – Day 1: Introduction & Setup

🎯 Goal:

• Understand what DSA is.

• Set up your C environment.

• Write your first C program.

• Learn about time & space complexity (theory).

• Practice basic input/output and loops.

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🧠 Theory: What is DSA?

• Data Structures = Ways to organize and store data efficiently.

• Algorithms = Step-by-step instructions to solve problems.

• Why DSA matters: Faster apps, better problem-solving, cracking tech interviews.

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🔧 Setup for C Programming

• Install a C compiler:

  • Windows: Use Code::Blocks or install MinGW and use VS Code.

  • Mac/Linux: Already comes with gcc. Use VS Code or terminal.

• Create your first .c file.

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👨‍💻 Hello World Program

#include <stdio.h>

int main() {
    printf("Hello, World!\n");
    return 0;
}

Compile using:

gcc hello.c -o hello
./hello

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📚 Time & Space Complexity (Intro)

• Big O Notation (O(n), O(1), etc.)

• Example:

  • Loop runs n times → O(n)

  • Constant statement → O(1)

Watch a quick 10 min video or read short notes on Big O notation.

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🧪 Practice: Basic C I/O and Loops

Tasks:

1. Take input of two numbers and print their sum.

2. Print numbers from 1 to n using a for loop.

3. Write a program to find if a number is even or odd.

Example:

#include <stdio.h>

int main() {
    int a, b;
    printf("Enter two numbers: ");
    scanf("%d %d", &a, &b);
    printf("Sum = %d\n", a + b);
    return 0;
}

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📅 Day 1 Summary

• ✅ Installed C

• ✅ Understood what DSA is

• ✅ Learned about time/space complexity

• ✅ Practiced basic C programs

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📘 Homework for Day 1:

• Write a program to find the factorial of a number.

• Write a program to print a multiplication table.

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🌟 Tomorrow: Arrays in C + Linear Search