Problem Solving with C++

Combine everything so far into one working program. In C++, planning matters even more than in higher-level languages: decide your data types and structures first, since changing them later often means touching several parts of the program at once.

• Sketch the data first: what values do you need, and what type is each one?
• Write and test one function at a time — don't try to write the whole program before compiling.
• Read compiler errors from the first one down; later errors are often side effects.
• Test with normal data, then edge cases (empty vector, zero, negative numbers).

💡 Practical Skill: This careful, incremental approach is exactly how professional C++ is written — small, compiled, tested increments, not one giant untested block of code.

#include <iostream>#include <vector>#include <string>#include <map> std::vector<std::string> checkStock(std::map<std::string, int>& inventory, int threshold) {    std::vector<std::string> lowStock;    for (auto& pair : inventory) {        if (pair.second < threshold) {            lowStock.push_back(pair.first);        }    }    return lowStock;} int main() {    std::map<std::string, int> inventory = {        {"exercise books", 120},        {"pens", 45},        {"chalk boxes", 8}    };     std::vector<std::string> reorder = checkStock(inventory, 10);     if (reorder.empty()) {        std::cout << "All stock levels are healthy." << std::endl;    } else {        std::cout << "Reorder needed for: ";        for (auto& item : reorder) std::cout << item << " ";        std::cout << std::endl;    }    return 0;}