C++ Foundations

A collection of early C++ console programs. Each source file builds to its own executable and demonstrates a core concept (I/O, arithmetic, selection, loops, arrays, functions, and C‑strings).

Tooling: CMake creates one executable per *.cpp (named after the file). The project targets C++20.

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📁 Project Layout

c-foundations/
├─ CMakeLists.txt
├─ README.md
├─ currency_denominations.cpp      # break amount into bills/coins
├─ merge_sorted_arrays.cpp         # two-pointer merge into one sorted array
├─ linked_list_basics.cpp          # singly linked list (ID/grade)
├─ sample_receipt.cpp              # formatted store receipt
├─ squares_in_circle.cpp           # area ratio: how many squares fit in a circle
├─ wage_calculator.cpp             # retail pay: hourly vs. commission
├─ eggfarm_batch_calculator.cpp    # egg batch totals, percentages, dozens
├─ pc_build_configurator.cpp       # PC builder & price estimator (functions)
├─ plastics_purchase_order.cpp     # recycled plastics purchase order
└─ password_helper.cpp             # password rules + confirmation (C-strings)

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🛠️ Prerequisites

• CMake ≥ 3.25
• A C++20 compiler
  • Windows: MSVC (Visual Studio 2022)
  • macOS: Apple Clang (Xcode tools)
  • Linux: GCC 12+ or Clang 15+

No third‑party libraries are required.

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🚀 Build Once, Run Any Program

From the repository root:

Windows (Visual Studio generator)

cmake -S . -B build -G "Visual Studio 17 2022"
cmake --build build --config Release
# Run any executable created by CMake:
.\build\Release\currency_denominations.exe
.\build\Release\merge_sorted_arrays.exe
.\build\Release\linked_list_basics.exe
.\build\Release\sample_receipt.exe
.\build\Release\squares_in_circle.exe
.\build\Release\wage_calculator.exe
.\build\Release\eggfarm_batch_calculator.exe
.\build\Release\pc_build_configurator.exe
.\build\Release\plastics_purchase_order.exe
.\build\Release\password_helper.exe

macOS / Linux (default Makefiles or Ninja)

cmake -S . -B build
cmake --build build -j
# Run any executable created by CMake:
./build/currency_denominations
./build/merge_sorted_arrays
./build/linked_list_basics
./build/sample_receipt
./build/squares_in_circle
./build/wage_calculator
./build/eggfarm_batch_calculator
./build/pc_build_configurator
./build/plastics_purchase_order
./build/password_helper

💡 CMake detects all *.cpp in the folder and makes one target per file. Add another Foo.cpp and rerun the two CMake commands above—CMake will generate a Foo executable automatically.

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📚 Program Index

Executable (target)	What it does	Core topics	Typical interaction
currency_denominations	Breaks a money amount into bills & coins (100s…1s, quarters…pennies).	integer arithmetic, modulo, formatting	Prompts for an amount like 123.45
merge_sorted_arrays	Merges two pre‑sorted arrays into a single sorted array via the two‑pointer merge step.	arrays, loops, algorithmic complexity	No input (arrays auto‑generated)
linked_list_basics	Creates and traverses a singly linked list of students (random ID, grade); counts total and A grades.	structs, pointers, traversal	No input
sample_receipt	Prints a formatted store receipt, sums subtotal, applies tax, and prints total.	I/O, constants, strings, arithmetic	No input
squares_in_circle	Computes how many squares fit inside a circle by area ratio (circle area ÷ square area).	I/O, iomanip, numeric constants	Prompts for circle diameter and square side
wage_calculator	Calculates an employee’s net pay using either hourly (with overtime) or commission tiers—whichever is higher.	input validation, conditionals, iomanip	Prompts for hours worked and weekly sales
eggfarm_batch_calculator	Aggregates an egg batch: totals white/brown, percentages, and dozens per type.	loops, validation, integer & floating‑point math	Prompts for baskets, then counts per basket
pc_build_configurator	PC configurator & pricer: choose CPU speed, storage, RAM, touchscreen; computes price.	functions, pass‑by‑reference, decomposition	Repeats builds until the user quits
plastics_purchase_order	Builds a recycled plastics purchase order with weights, unit prices, line totals, and grand totals.	arrays, table formatting	Prompts for pounds per plastic type
password_helper	Password helper that enforces: length 6–20, no spaces, at least one uppercase, lowercase, digit, and punctuation; then confirmation.	C‑strings, <cctype>, <cstring>, loops	Prompts until rules pass; then confirm

📝 Program Notes

currency_denominations — “Currency breakdown”

• Prompts for a money amount.
• Computes number of bills ($100…$1) and coins (quarters, dimes, nickels, pennies).
• Demonstrates integer division and modulo.

Run: ./currency_denominations

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merge_sorted_arrays — “Merge step”

• Generates two strictly increasing integer arrays.
• Uses the classic two‑pointer merge to produce a combined sorted array.

Run: ./merge_sorted_arrays (no input)

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linked_list_basics — “Student linked list”

• Builds a small linked list of Student nodes with random IDs and grades.
• Traverses the list, printing values, counting nodes, and tallying A grades.

Run: ./linked_list_basics (no input)

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sample_receipt — “Store receipt”

• Hard‑coded item names and prices; computes subtotal, tax, and total.
• Demonstrates formatted output and use of constants.

Run: ./sample_receipt (no input)

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squares_in_circle — “Squares in a circle”

• Asks for circle diameter and square side length.
• Computes areas and divides to estimate how many squares “fit” inside.

Run: ./squares_in_circle
Input: diameter, then square side

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wage_calculator — “Retail pay”

• Validates non‑negative hours and sales.
• Computes hourly pay (with overtime) vs commission (tiered) and prints the higher.

Run: ./wage_calculator
Input: hours worked, weekly sales

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eggfarm_batch_calculator — “Egg batch stats”

• Prompts for number of baskets, then counts white and brown eggs per basket.
• Prints totals, percentages, and dozen counts.

Run: ./eggfarm_batch_calculator
Input: num baskets, then counts for white and brown per basket

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pc_build_configurator — “PC builder & pricer”

• Three‑function design:
  • userInput(...) gathers selections.
  • calculateTotal(...) derives cost from base + increments.
  • displayBuild(...) prints results.
• Loops to allow multiple builds.

Run: ./pc_build_configurator
Input: CPU GHz, storage GB, RAM GB, touchscreen Y/N

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plastics_purchase_order — “Recycled plastics order”

• Parallel arrays for plastic types, prices, user‑entered weights, and line totals.
• Prints an aligned purchase order with totals.

Run: ./plastics_purchase_order
Input: pounds for each plastic type

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password_helper — “Password generator & validator”

• Enforces password rules: 6–20 chars, no spaces, ≥1 upper, lower, digit, punctuation.
• Prompts until valid, then requires re‑entry to confirm.

Run: ./password_helper
Input: password string, then confirmation

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🔧 Building Tips

• If you add new .cpp files at the top level, CMake will automatically create a new executable for each on the next configure/generate step.
• On Windows, the built executables live under build\{Debug|Release}\ when using Visual Studio generators.
• If a program appears to “hang,” it’s usually waiting for input—check the “Typical interaction” column or the “Run” notes above.

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✅ License / Usage

These are educational exercises; feel free to use, modify, and extend for learning purposes.