laba_3_3_c++

#include <iostream>
#include <fstream>
#include <string>
using namespace std;
ifstream fin;
ofstream fout;

int inputData() {
    int n = 0;
    bool isIncorrect;;
    do {
        cin >> n;
        isIncorrect = false;
        if (cin.fail()) {
            cout << "Please, enter an integer number:" << endl;
            isIncorrect = true;
            cin.clear();
            while (cin.get() != '\n');
        }
    } while (isIncorrect);
    return n;
}

bool choose() {
    int inputNumber;
    bool isIncorrect;
    const int MIN_NUM = 0;
    const int MAX_NUM = 1;
    do {
        inputNumber = inputData();
        isIncorrect = false;
        if (cin.fail()) {
            isIncorrect = true;
            cout << "Please, enter a number." << endl;
            cin.clear();
            while (cin.get() != '\n');
        }
        if (!isIncorrect && (inputNumber < MIN_NUM || inputNumber > MAX_NUM)) {
            cout << "You are out of input range!" << endl;
            isIncorrect = true;
        }
    } while (isIncorrect);
    if (inputNumber == 1)
        return true;
    else
        return false;
}

int inputArraySize() {
    bool isIncorrect;
    int num = 0;
    const int MIN_SIZE = 2;
    do {
        num = inputData();
        isIncorrect = false;
        if (num < MIN_SIZE) {
            cout << "Please, enter a number > 2:" << endl;
            isIncorrect = true;
            cin.clear();
            while (cin.get() != '\n');
        }
    } while (isIncorrect);
    return num;
}

int* inputArray(int num) {
    int* arr = new int[num];
    for (int i = 0; i < num; i++)
        arr[i] = inputData();
    return arr;
}

int* sortArrayBySelectionSort(int* arr, int num) {
    cout << "Sort stages:" << endl;
    int min;
    for (int i = 0; i < num - 1; i++) {
        for (int j = i + 1; j < num; j++)
            if (arr[j] < arr[i]) {
                min = arr[j];
                arr[j] = arr[i];
                arr[i] = min;
            }
        cout << "Stage " << (i + 1) << ": ";
        for (int j = 0; j < num; j++)
            cout << arr[j] << " ";
        cout << endl;
    }
    return arr;
}

void consoleOutput(int* arr, int num) {
    for (int i = 0; i < num; i++)
        cout << arr[i] << ' ';
    cout << endl;
}


string inputFilePath() {
    const int EXTENSION_SIZE = 4;
    string path;
    string ext;
    bool isIncorrect;
    do {
        isIncorrect = false;
        cout << "Input path to file: " << endl;
        cin >> path;
        fin.open(path);
        if (path.size() > EXTENSION_SIZE) {
            ext = path.substr(path.size() - EXTENSION_SIZE, EXTENSION_SIZE);
        }
        else {
            cout << "Incorrect file name." << endl;
            isIncorrect = true;
        } if (!isIncorrect && ext != ".txt") {
            cout << "Must have .txt!" << endl;
            isIncorrect = true;
        }
        else if (!isIncorrect && !fin.is_open()) {
            cout << "Wrong way to file." << endl;
            isIncorrect = true;
        }
    } while (isIncorrect);
    fin.close();
    return path;
}

int inputSizeOfArrayFromFile(string path) {
    int num;
    bool isIncorrect;
    const int MIN = 2;
    do{
        isIncorrect = false;
        fin.open(path);
        fin >> num;
        if (num < MIN) {
            isIncorrect = true;
            cout << "Matrix size should be at least 2" << endl;
            path = inputFilePath();
        }
    } while (isIncorrect);
    return num;
}

int* inputArrayFile (string path, int num){
    ifstream fileIn(path);
    bool isIncorrect = false;
    int* arr = new int [num];
    for (int i = 0; i < num; i++) {
        do {
            isIncorrect = false;
            fin >> arr[i];
            if (fin.fail()) {
                cout << "Reading of array elements failed." << endl;
                isIncorrect = true;
                path = inputFilePath();
            }
        } while (isIncorrect);
    }
    return arr;
}

void fileOutput(int* arr, string path, int num) {
    fout.open(path);
    fout << "Sorted array: " << endl;
    for (int i = 0; i < num; i++)
        fout << arr[i] << " ";
    cout << "Successful output in file." << endl;
    fout.close();
}
/* в c++ main отличается от остальных языков, так как нет функций input и output(в отличие от delphi и java).
Это из-за отсутствия функции, возвращающей длину массива(High(массив) или массив.length в других языках). */
int main() {
    cout << "Selection sort. Demonstration." << endl;;
    cout << "Enter type of input: " << '\n' << "1 is console input, 0 is file input." << endl;
    int num;
    int* arr;
    string path;
    bool chose = choose();
    if (chose) {
        cout << "Input size of array:" << endl;
        num = inputArraySize();
        cout << "Input array elements:" << endl;
        arr = inputArray(num);
        cout << "Unsorted array:" << endl;
        consoleOutput(arr, num);
    }
    else {
        path = inputFilePath();
        num = inputSizeOfArrayFromFile(path);
        arr = inputArrayFile(path, num);
    }
    arr = sortArrayBySelectionSort(arr, num);
    cout << "Enter type of output: " << '\n' << "1 is console output, 0 is file output." << endl;
    chose = choose();
    if (chose) {
        cout << "Sorted array:" << endl;
        consoleOutput(arr, num);
    }
    else {
        path = inputFilePath();
        fileOutput(arr, path, num);
    }
}