Programming Fundamentals Using C++

Project 6 — The Inventory Management System

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Overview

The campus store’s back office: a stockroom of products (name, quantity, price) with a menu for restocking, selling, searching (by name, by price ceiling), a low-stock report, a value report, and sorting (by name, by quantity, by price). No files yet — this project is the data mechanics layer that Project 7 and 9 will persist.

Learning objectives

Prerequisites

Unit What you need
09 arrays/vector, passing collections
10 linear/binary search, selection sort
11 std::string comparison and formatting

Requirements

  1. Data: up to 100 products — name (unique, one word), quantity (≥ 0), price (0.01–10000). Load by typing n products at startup (a seed function).
  2. Menu: 1 list · 2 restock · 3 sell · 4 search by name · 5 search “affordable” (price ≤ X) · 6 low-stock report · 7 sort (name/qty/price) · 8 value report · 0 quit.
  3. Restock/sell are ask-doors by name; sell refuses beyond stock.
  4. Sorting offers all three keys, on copies or in place (state which); the name↔qty↔price pairing must survive.
  5. Value report: per-line and total stock value.

Functional requirements

ID Statement Verified by
F1 list prints all products in columns T1
F2 sell beyond stock is refused, stock unchanged T2
F3 search by name finds or reports not found T3
F4 affordable search lists every product ≤ X T4
F5 all three sorts produce correct orders with pairing intact T5
F6 value report totals correctly to 2 decimals T6

Suggested data structures

Milestones

Tasks

  1. Write the seed reader and listAll.
  2. Write findProduct; build restock/sell on it.
  3. Write the two searches.
  4. Write the sorts — start with by-name selection sort, then generalise the key.
  5. Write the two reports; walk the test plan.

Test plan

# Seed & sequence Expected
T1 seed 3 products → list all three, aligned columns
T2 sell 5 of qty 3 refusal; list unchanged
T3 search Pen (exists), Zed (doesn’t) found with details / not found
T4 affordable ≤ 1.00 every product ≤ 1.00 listed
T5 sort by qty → list → sort by name → list both orders correct, pairings right
T6 value report with known data per-line and total exact

Edge cases

Extension ideas

  1. A reorder report with target quantities (the Level 3 lab’s rule, revisited here).
  2. Binary search on the price-sorted copy (the algorithms module’s precondition, exercised).
  3. Undo the last movement (a small action history).

Grading / self-assessment

Shared rubric plus:

Hints

  1. The sort’s swap is three swaps (name, qty, price) — miss one and the stockroom lies. Write a swapProduct(i, j) helper so the three swaps exist once.
  2. The affordable search is a filter scan (print every match), not a find-one — different shape than findProduct.
  3. Value report: qty * price per line; accumulate in double; print with setprecision(2).

Complete reference solution

// stockroom.cpp — Programming Fundamentals Using C++
// Project 6 · The Inventory Management System
// Build: g++ -std=c++17 -Wall -Wextra stockroom.cpp -o stockroom

#include <iostream>
#include <iomanip>
#include <string>
#include <vector>
using namespace std;

const int MAX_PRODUCTS = 100;
const double PRICE_MIN = 0.01, PRICE_MAX = 10000.0;

int findProduct(const vector<string>& names, const string& target) {
    for (size_t i = 0; i < names.size(); ++i)
        if (names[i] == target) return static_cast<int>(i);
    return -1;
}

void seed(vector<string>& names, vector<int>& quantities, vector<double>& prices) {
    int n;
    cout << "How many products to enter (1-" << MAX_PRODUCTS << "): ";
    cin >> n;
    while (n < 1 || n > MAX_PRODUCTS) { cout << "1-" << MAX_PRODUCTS << ": "; cin >> n; }

    for (int i = 0; i < n; ++i) {
        string name; int qty; double price;
        cout << "Product " << (i + 1) << " name: ";
        cin >> name;
        while (findProduct(names, name) != -1) {   // uniqueness at entry
            cout << "Name already exists. Again: ";
            cin >> name;
        }
        cout << "quantity: ";
        cin >> qty;
        while (qty < 0) { cout << "Cannot be negative: "; cin >> qty; }
        cout << "price: ";
        cin >> price;
        while (price < PRICE_MIN || price > PRICE_MAX) {
            cout << "Price is 0.01-10000: ";
            cin >> price;
        }
        names.push_back(name);                    // the pairing transaction
        quantities.push_back(qty);
        prices.push_back(price);
    }
}

void listAll(const vector<string>& names, const vector<int>& quantities,
             const vector<double>& prices) {
    if (names.empty()) { cout << "Stockroom empty\n"; return; }
    cout << left << setw(12) << "Name" << right << setw(8) << "Qty"
         << setw(12) << "Price" << "\n";
    for (size_t i = 0; i < names.size(); ++i)
        cout << left << setw(12) << names[i] << right << setw(8) << quantities[i]
             << setw(12) << fixed << setprecision(2) << prices[i] << "\n";
}

void moveStock(vector<string>& names, vector<int>& quantities, bool receiving) {
    cout << "Product name: ";
    string name; cin >> name;
    int idx = findProduct(names, name);
    if (idx == -1) { cout << "No such product\n"; return; }

    cout << "Amount: ";
    int amt; cin >> amt;
    while (amt < 1) { cout << "At least 1: "; cin >> amt; }

    if (receiving) {
        quantities[idx] += amt;
        cout << "Received — qty " << quantities[idx] << "\n";
    } else if (amt > quantities[idx]) {
        cout << "Refused: only " << quantities[idx] << " in stock\n";
    } else {
        quantities[idx] -= amt;                   // sell-to-zero is legal
        cout << "Sold — qty " << quantities[idx] << "\n";
    }
}

void affordableSearch(const vector<string>& names, const vector<int>& quantities,
                      const vector<double>& prices) {
    cout << "Maximum price: ";
    double cap; cin >> cap;
    bool any = false;
    for (size_t i = 0; i < names.size(); ++i)
        if (prices[i] <= cap) {
            cout << "  " << names[i] << " (qty " << quantities[i]
                 << ", Rs " << fixed << setprecision(2) << prices[i] << ")\n";
            any = true;
        }
    if (!any) cout << "Nothing at or under that price\n";
}

void sortStock(vector<string>& names, vector<int>& quantities, vector<double>& prices,
               int key) {
    for (size_t i = 0; i + 1 < names.size(); ++i) {       // selection sort by key
        size_t best = i;
        for (size_t j = i + 1; j < names.size(); ++j) {
            bool smaller = false;
            if (key == 1)      smaller = names[j] < names[best];
            else if (key == 2) smaller = quantities[j] < quantities[best];
            else               smaller = prices[j] < prices[best];
            if (smaller) best = j;
        }
        if (best != i) {                                   // the pairing swap, once
            swap(names[i], names[best]);
            swap(quantities[i], quantities[best]);
            swap(prices[i], prices[best]);
        }
    }
    cout << "Sorted\n";
}

void valueReport(const vector<string>& names, const vector<int>& quantities,
                 const vector<double>& prices) {
    if (names.empty()) { cout << "Stockroom empty\n"; return; }
    double total = 0.0;
    cout << fixed << setprecision(2);
    for (size_t i = 0; i < names.size(); ++i) {
        double value = quantities[i] * prices[i];
        cout << "  " << names[i] << ": " << quantities[i] << " x Rs " << prices[i]
             << " = Rs " << value << "\n";
        total += value;
    }
    cout << "  TOTAL: Rs " << total << "\n";
}

int main() {
    vector<string> names;
    vector<int> quantities;
    vector<double> prices;

    cout << "=== Stockroom ===\n";
    seed(names, quantities, prices);

    int choice;
    do {
        cout << "\n1 List · 2 Restock · 3 Sell · 4 Find · 5 Affordable · "
                "6 Sort · 7 Value · 0 Quit: ";
        cin >> choice;

        if (choice == 1) {
            listAll(names, quantities, prices);
        } else if (choice == 2 || choice == 3) {
            moveStock(names, quantities, choice == 2);
        } else if (choice == 4) {
            cout << "Product name: ";
            string name; cin >> name;
            int idx = findProduct(names, name);
            if (idx == -1) cout << "Not found\n";
            else cout << "  " << names[idx] << " qty " << quantities[idx]
                      << " Rs " << fixed << setprecision(2) << prices[idx] << "\n";
        } else if (choice == 5) {
            affordableSearch(names, quantities, prices);
        } else if (choice == 6) {
            cout << "Sort by 1 name / 2 quantity / 3 price: ";
            int key; cin >> key;
            if (key >= 1 && key <= 3) sortStock(names, quantities, prices, key);
            else cout << "Invalid key\n";
        } else if (choice == 7) {
            valueReport(names, quantities, prices);
        } else if (choice != 0) {
            cout << "Invalid choice\n";
        }
    } while (choice != 0);

    cout << "Goodbye — " << names.size() << " product(s) on file\n";
    return 0;
}

Explanation of important design decisions

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— Engr. Dr. Muhammad Nadeem Majeed, Professor, Department of Data Science (PUCIT), University of the Punjab, Lahore · About the instructor