Lottery.cpp

#include <iostream>
#include <vector>

using namespace std;

#define NUMBER_AMOUNT 6
#define INPUT_LOWER_BOUND 1
#define INPUT_UPPER_BOUND 59

string* rewards = new string[NUMBER_AMOUNT + 1] { "Nothing.", "One Free Lucky Dip", "£25", "~£100", "~£1,000", "~£50,000", "Jackpot" };

vector<int> getUserGuesses(int amount, int lowerBound, int upperBound);
int getInteger(int lowerBound, int upperBound);
void sort(vector<int> &numbers);
void swap(int &a, int &b);
string intArrayToString(vector<int> array, string deliminator);
vector<int> generateRandomNumbers(int amount, int lowerBound, int upperBound);
int generateRandomNumber(int lowerBound, int upperBound);
vector<int> getMatches(vector<int> winningNumbers, vector<int> userNumbers);
void showMatches(vector<int> matches);

int main() {
    srand((unsigned int) time(NULL)); // set random seed

    // get and display user input
    cout << "Please enter " << NUMBER_AMOUNT << " numbers." << endl;
    vector<int> inputs = getUserGuesses(NUMBER_AMOUNT, INPUT_LOWER_BOUND, INPUT_UPPER_BOUND);
    sort(inputs);
    cout << "Your numbers: " << intArrayToString(inputs, ", ") << endl;

    // generate and display winning numbers
    vector<int> winningNumbers = generateRandomNumbers(NUMBER_AMOUNT, INPUT_LOWER_BOUND, INPUT_UPPER_BOUND);
    sort(winningNumbers);
    cout << "Winning numbers: " << intArrayToString(winningNumbers, ", ") << endl;

    // get and show matching numbers
    vector<int> matchingNumbers = getMatches(winningNumbers, inputs);
    sort(matchingNumbers);
    showMatches(matchingNumbers);
}

vector<int> getUserGuesses(int amount, int lowerBound, int upperBound) {
    vector<int> inputs((size_t) amount);

    for (int i = 0; i < amount; i++) {
        inputs[i] = getInteger(lowerBound, upperBound);
    }

    return inputs;
}

int getInteger(int lowerBound, int upperBound) {
    int input;
    cin >> input;

    if (cin.fail()) {
        cout << "Not an integer." << endl;
        input = getInteger(lowerBound, upperBound);
    }

    if (input < lowerBound || input > upperBound) {
        cout << "Please enter a number in the range " << lowerBound << "-" << upperBound << endl;
        input = getInteger(lowerBound, upperBound);
    }

    return input;
}

void sort(vector<int> &numbers) {
    long size = numbers.size();

    for (int count1 = 0; count1 < size; count1++) {
        for (int count2 = 0; count2 < size; count2++) {
            int nextIndex = count2 + 1;

            if (nextIndex < size && numbers[count2] > numbers[nextIndex]) {
                swap(numbers[count2], numbers[nextIndex]);
            }
        }
    }
}

void swap(int &a, int &b) {
    int aCopy = a;
    a = b;
    b = aCopy;
}

string intArrayToString(vector<int> array, string deliminator) {
    string output = "";

    for (int i  = 0; i < array.size(); i++) {
        output += to_string(array[i]);

        if (i != array.size() - 1) {
            output += deliminator;
        }
    }

    return output;
}

vector<int> generateRandomNumbers(int amount, int lowerBound, int upperBound) {
    vector<int> numbers((size_t) amount);

    for (int i = 0; i < amount; i++) {
        numbers[i] = generateRandomNumber(lowerBound, upperBound);
    }

    return numbers;
}

int generateRandomNumber(int lowerBound, int upperBound) {
    return lowerBound + (rand() % (upperBound - lowerBound + 1));
}

vector<int> getMatches(vector<int> winningNumbers, vector<int> userNumbers) {
    vector<int> matches(winningNumbers.size()); // this can only ever be as big as winningNumbers.size()
    int matchesIndex = 0;

    for (int i = 0; i < winningNumbers.size(); i++) {
        int winningNumber = winningNumbers[i];

        for (int j = 0; j < userNumbers.size(); j++) {
            int userNumber = userNumbers[j];

            if (userNumber == winningNumber) {
                matches[matchesIndex++] = winningNumber;
            }
        }
    }

    // downsize if we didn't use the full capacity of the vector
    matches.resize((size_t) matchesIndex);

    return matches;
}

void showMatches(vector<int> matches) {
    int matchAmount = (int) matches.size();

    if (matchAmount > 0) {
        cout << matches.size() << " matches (" << rewards[matchAmount] << ")" << endl;
        cout << "Matching Numbers: " << intArrayToString(matches, ", ") << endl;
    } else {
        cout << "No matches this time, sorry!" << endl;
    }
}