feat: implemented unit converter

Src/Unit_converter/unit_converter.cpp

@@ -0,0 +1,193 @@
+#include <iostream>
+#include <limits>
+#include <iomanip>
+#include <cmath>
+using namespace std;
+
+void clearInput() {
+    cin.clear();
+    cin.ignore(numeric_limits<streamsize>::max(), '\n');
+}
+
+double getNumber(const string &prompt) {
+    double x;
+    while (true) {
+        cout << prompt;
+        if (cin >> x) {
+            clearInput();
+            return x;
+        }
+        cout << "Invalid number. Try again.\n";
+        clearInput();
+    }
+}
+
+int getIntInRange(const string &prompt, int lo, int hi) {
+    int c;
+    while (true) {
+        cout << prompt;
+        if (cin >> c) {
+            clearInput();
+            if (c >= lo && c <= hi) return c;
+            cout << "Choice out of range (" << lo << " - " << hi << "). Try again.\n";
+        } else {
+            cout << "Invalid input. Enter a number.\n";
+            clearInput();
+        }
+    }
+}
+
+namespace conv {
+    double metersToKilometers(double m) { return m / 1000.0; }
+    double kilometersToMeters(double km) { return km * 1000.0; }
+    double metersToMiles(double m) { return m / 1609.344; }
+    double milesToMeters(double mi) { return mi * 1609.344; }
+    double feetToMeters(double ft) { return ft * 0.3048; }
+    double metersToFeet(double m) { return m / 0.3048; }
+
+    double cToF(double c) { return (c * 9.0/5.0) + 32.0; }
+    double fToC(double f) { return (f - 32.0) * 5.0/9.0; }
+    double cToK(double c) { return c + 273.15; }
+    double kToC(double k) { return k - 273.15; }
+
+    double gramsToKilograms(double g) { return g / 1000.0; }
+    double kilogramsToGrams(double kg) { return kg * 1000.0; }
+    double kilogramsToPounds(double kg) { return kg * 2.2046226218; }
+    double poundsToKilograms(double lb) { return lb / 2.2046226218; }
+
+    double litersToMilliliters(double L) { return L * 1000.0; }
+    double millilitersToLiters(double mL) { return mL / 1000.0; }
+    double litersToGallons(double L) { return L * 0.2641720524; }
+    double gallonsToLiters(double gal) { return gal / 0.2641720524; }
+}
+
+void pressEnterToContinue() {
+    cout << "\nPress ENTER to continue...";
+    cin.get();
+}
+
+void lengthMenu() {
+    while (true) {
+        cout << "\n--- Length Converter ---\n";
+        cout << "1) Meters → Kilometers\n";
+        cout << "2) Kilometers → Meters\n";
+        cout << "3) Meters → Miles\n";
+        cout << "4) Miles → Meters\n";
+        cout << "5) Feet → Meters\n";
+        cout << "6) Meters → Feet\n";
+        cout << "7) Back to Main Menu\n";
+        int ch = getIntInRange("Choose (1-7): ", 1, 7);
+        if (ch == 7) return;
+
+        double v = getNumber("Enter value: ");
+        cout << fixed << setprecision(6);
+        switch (ch) {
+            case 1: cout << v << " m = " << conv::metersToKilometers(v) << " km\n"; break;
+            case 2: cout << v << " km = " << conv::kilometersToMeters(v) << " m\n"; break;
+            case 3: cout << v << " m = " << conv::metersToMiles(v) << " miles\n"; break;
+            case 4: cout << v << " miles = " << conv::milesToMeters(v) << " m\n"; break;
+            case 5: cout << v << " ft = " << conv::feetToMeters(v) << " m\n"; break;
+            case 6: cout << v << " m = " << conv::metersToFeet(v) << " ft\n"; break;
+        }
+        pressEnterToContinue();
+    }
+}
+
+void temperatureMenu() {
+    while (true) {
+        cout << "\n--- Temperature Converter ---\n";
+        cout << "1) Celsius → Fahrenheit\n";
+        cout << "2) Fahrenheit → Celsius\n";
+        cout << "3) Celsius → Kelvin\n";
+        cout << "4) Kelvin → Celsius\n";
+        cout << "5) Back to Main Menu\n";
+        int ch = getIntInRange("Choose (1-5): ", 1, 5);
+        if (ch == 5) return;
+
+        double v = getNumber("Enter value: ");
+        cout << fixed << setprecision(4);
+        switch (ch) {
+            case 1: cout << v << " °C = " << conv::cToF(v) << " °F\n"; break;
+            case 2: cout << v << " °F = " << conv::fToC(v) << " °C\n"; break;
+            case 3: cout << v << " °C = " << conv::cToK(v) << " K\n"; break;
+            case 4: cout << v << " K = " << conv::kToC(v) << " °C\n"; break;
+        }
+        pressEnterToContinue();
+    }
+}
+
+void weightMenu() {
+    while (true) {
+        cout << "\n--- Weight Converter ---\n";
+        cout << "1) Grams → Kilograms\n";
+        cout << "2) Kilograms → Grams\n";
+        cout << "3) Kilograms → Pounds\n";
+        cout << "4) Pounds → Kilograms\n";
+        cout << "5) Back to Main Menu\n";
+        int ch = getIntInRange("Choose (1-5): ", 1, 5);
+        if (ch == 5) return;
+
+        double v = getNumber("Enter value: ");
+        cout << fixed << setprecision(6);
+        switch (ch) {
+            case 1: cout << v << " g = " << conv::gramsToKilograms(v) << " kg\n"; break;
+            case 2: cout << v << " kg = " << conv::kilogramsToGrams(v) << " g\n"; break;
+            case 3: cout << v << " kg = " << conv::kilogramsToPounds(v) << " lb\n"; break;
+            case 4: cout << v << " lb = " << conv::poundsToKilograms(v) << " kg\n"; break;
+        }
+        pressEnterToContinue();
+    }
+}
+
+void volumeMenu() {
+    while (true) {
+        cout << "\n--- Volume Converter ---\n";
+        cout << "1) Liters → Milliliters\n";
+        cout << "2) Milliliters → Liters\n";
+        cout << "3) Liters → Gallons (US)\n";
+        cout << "4) Gallons (US) → Liters\n";
+        cout << "5) Back to Main Menu\n";
+        int ch = getIntInRange("Choose (1-5): ", 1, 5);
+        if (ch == 5) return;
+
+        double v = getNumber("Enter value: ");
+        cout << fixed << setprecision(6);
+        switch (ch) {
+            case 1: cout << v << " L = " << conv::litersToMilliliters(v) << " mL\n"; break;
+            case 2: cout << v << " mL = " << conv::millilitersToLiters(v) << " L\n"; break;
+            case 3: cout << v << " L = " << conv::litersToGallons(v) << " gal\n"; break;
+            case 4: cout << v << " gal = " << conv::gallonsToLiters(v) << " L\n"; break;
+        }
+        pressEnterToContinue();
+    }
+}
+
+// --- Main ---
+void printMainMenu() {
+    cout << "\n=============================\n";
+    cout << "      UNIT CONVERTER\n";
+    cout << "=============================\n";
+    cout << "1) Length\n";
+    cout << "2) Temperature\n";
+    cout << "3) Weight\n";
+    cout << "4) Volume\n";
+    cout << "5) Exit\n";
+}
+
+int main() {
+    cout << "Simple Unit Converter (console)\n";
+    while (true) {
+        printMainMenu();
+        int ch = getIntInRange("Choose (1-5): ", 1, 5);
+        switch (ch) {
+            case 1: lengthMenu(); break;
+            case 2: temperatureMenu(); break;
+            case 3: weightMenu(); break;
+            case 4: volumeMenu(); break;
+            case 5:
+                cout << "Goodbye!\n";
+                return 0;
+        }
+    }
+    return 0;
+}