feat: Implement C++ Currency Converter (#4)

Author: saumya1317

Src/Currency_Converter/conv.cpp

@@ -0,0 +1,37 @@
+#include "conv.h"
+
+CurrencyConverter::CurrencyConverter() {}
+
+void CurrencyConverter::addCurrency(const Currency& currency) {
+    currencies[currency.getCode()] = currency;
+}
+
+void CurrencyConverter::setExchangeRate(const string& fromCurrency, const string& toCurrency, double rate) {
+    if (rate <= 0)
+        throw invalid_argument("Invalid rate");
+    exchangeRates[fromCurrency + toCurrency] = rate;
+}
+
+double CurrencyConverter::getExchangeRate(const string& fromCurrency, const string& toCurrency) const {
+    auto it = exchangeRates.find(fromCurrency + toCurrency);
+    if (it == exchangeRates.end())
+        throw invalid_argument("Exchange rate not found");
+    return it->second;
+}
+
+bool CurrencyConverter::hasCurrency(const string& code) const {
+    return currencies.find(code) != currencies.end();
+}
+
+vector<Currency> CurrencyConverter::listCurrencies() const {
+    vector<Currency> result;
+    for (auto& x : currencies)
+        result.push_back(x.second);
+    return result;
+}
+
+double CurrencyConverter::convert(double amount, const string& fromCurrency, const string& toCurrency) const {
+    if (!hasCurrency(fromCurrency) || !hasCurrency(toCurrency))
+        throw invalid_argument("Invalid currency code");
+    return amount * getExchangeRate(fromCurrency, toCurrency);
+}

Src/Currency_Converter/conv.h

@@ -0,0 +1,18 @@
+#ifndef CURRENCYCONVERTER_H
+#define CURRENCYCONVERTER_H
+#include <bits/stdc++.h>
+#include "cur.h"
+using namespace std;
+class CurrencyConverter {
+    map<string, Currency> currencies;
+    map<string, double> exchangeRates;
+public:
+    CurrencyConverter();
+    void addCurrency(const Currency& currency);
+    void setExchangeRate(const string& fromCurrency, const string& toCurrency, double rate);
+    double convert(double amount, const string& fromCurrency, const string& toCurrency) const;
+    bool hasCurrency(const string& code) const;
+    double getExchangeRate(const string& fromCurrency, const string& toCurrency) const;
+    vector<Currency> listCurrencies() const;
+};
+#endif

Src/Currency_Converter/cur.cpp

@@ -0,0 +1,16 @@
+#include "cur.h"
+
+Currency::Currency(const string& code, const string& name, const string& symbol)
+    : code(code), name(name), symbol(symbol) {}
+
+string Currency::getCode() const {
+    return code;
+}
+
+string Currency::getName() const {
+    return name;
+}
+
+string Currency::getSymbol() const {
+    return symbol;
+}

Src/Currency_Converter/cur.h

@@ -0,0 +1,13 @@
+#ifndef CURRENCY_H
+#define CURRENCY_H
+#include <bits/stdc++.h>
+using namespace std;
+class Currency {
+    string code, name, symbol;
+public:
+    Currency(const string& code, const string& name, const string& symbol);
+    string getCode() const;
+    string getName() const;
+    string getSymbol() const;
+};
+#endif

Src/Currency_Converter/main.cpp

@@ -0,0 +1,83 @@
+#include <bits/stdc++.h>
+#include "cur.h"
+#include "conv.h"
+using namespace std;
+using nlim = numeric_limits<streamsize>;
+
+void show(const CurrencyConverter& converter) {
+    for (auto& currency : converter.listCurrencies())
+        cout << currency.getCode() << "-" << currency.getName() << "(" << currency.getSymbol() << ")\n";
+    cout << endl;
+}
+
+int main() {
+    CurrencyConverter converter;
+    converter.addCurrency(Currency("USD", "US Dollar", "$"));
+    converter.addCurrency(Currency("EUR", "Euro", "€"));
+    converter.addCurrency(Currency("INR", "Indian Rupee", "₹"));
+    converter.addCurrency(Currency("GBP", "British Pound", "£"));
+    converter.setExchangeRate("USD", "INR", 83.0);
+    converter.setExchangeRate("INR", "USD", 0.012);
+    converter.setExchangeRate("USD", "EUR", 0.93);
+    converter.setExchangeRate("EUR", "USD", 1.08);
+    converter.setExchangeRate("USD", "GBP", 0.79);
+    converter.setExchangeRate("GBP", "USD", 1.27);
+    converter.setExchangeRate("EUR", "INR", 89.0);
+    converter.setExchangeRate("INR", "EUR", 0.011);
+    int choice;
+    do {
+        cout << "\nMenu:\n1.List\n2.Convert\n3.Update\n0.Exit\n> ";
+        cin >> choice;
+        cin.ignore(nlim::max(),'\n');
+        if (choice == 1) {
+            show(converter);
+        } else if (choice == 2) {
+            string fromCurrency, toCurrency;
+            double amount;
+            cout << "From: ";
+            cin >> fromCurrency;
+            cout << "To: ";
+            cin >> toCurrency;
+            cout << "Amount: ";
+            cin >> amount;
+            if (cin.fail() || amount <= 0) {
+                cout << "Invalid input\n";
+                cin.clear();
+                cin.ignore(nlim::max(),'\n');
+                continue;
+            }
+            try {
+                double result = converter.convert(amount, fromCurrency, toCurrency);
+                cout << fixed << setprecision(2) << amount << fromCurrency << "=" << result << toCurrency << "\n";
+            } catch (const exception& e) {
+                cout << "Error: " << e.what() << "\n";
+            }
+        } else if (choice == 3) {
+            string fromCurrency, toCurrency;
+            double rate;
+            cout << "From: ";
+            cin >> fromCurrency;
+            cout << "To: ";
+            cin >> toCurrency;
+            cout << "Rate(1" << fromCurrency << "=" << toCurrency << "): ";
+            cin >> rate;
+            if (cin.fail() || rate <= 0) {
+                cout << "Invalid rate\n";
+                cin.clear();
+                cin.ignore(nlim::max(),'\n');
+                continue;
+            }
+            try {
+                converter.setExchangeRate(fromCurrency, toCurrency, rate);
+                cout << "Updated\n";
+            } catch (const exception& e) {
+                cout << "Error: " << e.what() << "\n";
+            }
+        } else if (choice == 0) {
+            cout << "bye\n";
+        } else {
+            cout << "bad\n";
+        }
+    } while (choice != 0);
+    return 0;
+}