Programming Basics and Preparation Guide by Striver

Introduction

• Welcome to the channel (Striver in the programming community).
• Connect on LinkedIn, Twitter, Instagram, and Telegram.
• Full-fledged interview preparation website: Strivers’ SDE sheet.

Resources Provided

• Strivers SDE Sheet: 191 problems covering all DS algo concepts for interview prep.
• Strivers A to Z DSA Course: 455 steps with problem links and videos for beginners and intermediates.
• Coding Ninjas: Mentioned for other programming courses.

C++ Programming Basics

Skeleton of C++ Code

• Starts with #include directives (e.g., #include <iostream>).
• Use namespaces to avoid repetition (using namespace std;).
• int main() { } is the entry point of the program.

Input and Output

• cin for input, cout for output.
• Use std::cin and std::cout if not using namespace.
• Use or std::endl for new lines.
• Prefer for faster execution.

Data Types

• Integer Types: int, long, long long.
• Floating Point: float, double.
• Character and String: char, string.
• Input/Output for String: cin for word inputs, getline(cin, str) for full line inputs.

Control Statements

If-Else Statements

• Syntax: if (condition) { } else { }.
• Use logical operators: && (AND), || (OR).
• Example: Determine adulthood by age.

Nested If-Else

• Inner if-else inside outer if-else for multiple conditions.
• Example: Print grade based on marks.

Switch Statements

• Syntax: switch (variable) { case value1: //code; break; ... default: //code; }.
• Use break to prevent fall-through.
• Example: Print day of the week based on number.

Arrays and Strings

One-Dimensional Arrays

• Declaration: int arr[5];.
• Access elements using index: arr[0], arr[1], ....

Two-Dimensional Arrays

• Declaration: int arr2D[3][5];.
• Access elements using indices: arr2D[0][0], arr2D[1][4], ....

String Manipulation

• Strings as arrays of characters.
• Access elements using indices: str[0], str[1], ....
• Use .length() or .size() for length of string.

Loops

For Loops

• Syntax: for (initialization; condition; increment) { }.
• Example: Print a name multiple times.

While Loops

• Syntax: while (condition) { }.

Do-While Loops

• Syntax: do { } while (condition);.
• Ensures the loop runs at least once.

Functions

Void Functions

• Syntax: void functionName() { }.
• Doesn't return a value.
• Can be parameterized or non-parameterized.

Return Functions

• Syntax: returnType functionName(parameters) { return value; }.

Pass by Value vs. Pass by Reference

• Pass by Value: Passes a copy, original remains unchanged.
• Pass by Reference: Use & to pass the original, changes affect original.

Additional Topics

Built-in Functions

• Example: min(), max() in <algorithm>.

Example Problems and Solutions

• Write a program that prints if a person is an adult based on age.
• Write a program that calculates sum of two numbers using functions.

Conclusion

• Stay tuned for more educational videos on data structures and algorithms.
• Follow Striver on social media for updates.