Homework4

## 1

#include <iostream>
#include <fstream>
using namespace std;
int main()
{
    system("chcp 1251");
    ofstream fileout("input.txt");
    // Установить начальную точку генерирования последовательности
    srand(31);
    for (int i = 0; i < 10; i++) {
        fileout << rand()<<"\n";
    }

    int s=0;
    fileout.close();
    ifstream filein ("input.txt");
    int number;
    if (filein) {
        for (int i = 0; i < 10; i++) {
            filein >> number;
            s += number;
        }
        cout << "Сумма чисел: " << s;
    }
    else {
        cout << "Нету такого файла(";
    }
    filein.close();
}





## 2
#include <iostream>
using namespace std;

int sign(float x) {
    if (x > 0)
        return 1;
    else if (x == 0)
        return 0;
    else
        return -1;
}

int main()
{
    system("chcp 1251");
    cout << "Задача «Знак числа»\n";
    cout << "x = ";
    float x;
    cin >> x;
    cout << "sign(x) = " << sign(x);
}

## 3
#define _USE_MATH_DEFINES
#include <cmath>
#include <iostream>
using namespace std;

double area_rectangle() {
    cout << "Площадь прямоугольника\n";
    double a,b;
    cout << "a = ";
    cin >> a;
    cout << "b = ";
    cin >> b;
    return a * b;
}
double area_triangle() {
    cout << "Площадь треугольника\n";
    double a, h;
    cout << "a = ";
    cin >> a;
    cout << "h = ";
    cin >> h;
    return 0.5*a*h;
}
double area_circle() {
    cout << "Площадь круга\n";
    double r;
    cout << "r = ";
    cin >> r;
    return M_PI*r*r;
}





int main()
{
    system("chcp 1251");
    cout << "Задача «Геометрические фигуры»\n";
    cout << "Укажите, площадь какой фигуры нужно вычислить\n\t1 - прямоугольник\n\t2 - треугольник\n\t3 - круг\n";
    int n;
    cin >> n;
    switch (n)
    {
    case 1:
        cout<<area_rectangle();
        break;
    case 2:
        cout << area_triangle();
        break;
    case 3:
        cout << area_circle();
        break;
    }
}



## 4
#include <iostream>

using namespace std;
#include <windows.h>

string symb_k_times(string symb, int k) {
    string result = "";
    for (int i = 0; i < k; i++)
        result += symb;
    return result;
}

int main()
{
    HANDLE h = GetStdHandle(STD_OUTPUT_HANDLE);

    system("chcp 1251");
    cout << "Задача «Былая слава»\n";
    SetConsoleTextAttribute(h, 0);
    int fl = 1;
    cout << symb_k_times(" ", 44)+"\n";
    for (int i = 0; i < 6; i++) {
        fl = (fl + 1) % 2;
        SetConsoleTextAttribute(h, 63);
        cout << " "+symb_k_times("* ", 8);

        SetConsoleTextAttribute(h, 200+fl*55);
        cout<<symb_k_times("_", 27) + "\n";
    }

    SetConsoleTextAttribute(h, 255);

    for (int i = 0; i < 7; i++) {
        fl = (fl + 1) % 2;
        SetConsoleTextAttribute(h, 200 + fl * 55);
        cout <<symb_k_times("_", 44)+"\n";
    }
    SetConsoleTextAttribute(h, 0);
    return 0;

}

## 5
#include <iostream>
#include <math.h>
using namespace std;
int main() {
    int height = 40;
    int width = 120;
    char A[100][200];
    for (int i = 0; i < height; i++) {
        for (int j = 0; j < width; j++) {
            A[i][j]='O';
        }
    }
    int y;
    for (int i = -width/2+2; i < width/2-2; i++) {
        y = sin((float) i/10)*10;
        A[y+height/2][i+width/2] = ' ';
    }

    for (int i = 0; i < width; i++)
        A[height/2][i] = '-';

    for (int i = 0; i < height; i++)
        A[i][width/2] = '|';



    A[height / 2][width - 1] = '>';
    A[0][width/2] = '^';
    A[height / 2][width / 2] = '+';


    for (int i = 0; i < height; i++) {
        for (int j = 0; j < width; j++) {
            cout<<A[i][j];
        }
        cout << "\n";
    }



    //a = sin(b)
    return 0;
}


## 6
#include <iostream>
#include <map>
#include <string>
#include <fstream>
#include <vector>

using namespace std;

int main()
{
    system("chcp 1251");
    map<string, int> m = {
        {"I", 1}, {"II", 2},{"III", 3},{"IV", 4},{"V", 5},{"VI", 6},{"VII", 7},{"VIII", 8},{"IX", 9},
        {"X", 10}, {"XX", 20}, {"XXX", 30}, {"XL", 40}, {"L", 50}, {"LX", 60}, {"LXX", 70}, {"LXXX", 80}, {"XC", 90},
        { "C", 100 }, { "CC", 200 }, { "CCC", 300 }, { "CD", 400 }, { "D", 500 }, { "DC", 600 }, { "DCC", 700 }, { "DCCC", 800 }, { "CM", 900 },
        { "M", 1000 } , { "MM", 2000 }, { "MMM", 3000 }
    };
    //['I', 'V', 'X', 'L', "C", 'D', 'M']
    string inp;
    cout << "roman_number = ";
    cin >> inp;
    int n = inp.length();


    int i = 0;
    string buff="";
    bool was_error = false;

    vector<int> v;
    while (i < inp.length()) {
        if (m.count(buff + inp[i])) {
            buff += inp[i];

        }
        else if (!(inp[i] == 'I' || inp[i] == 'V' || inp[i] == 'X' || inp[i] == 'L' || inp[i] == 'C' || inp[i] == 'D' || inp[i] == 'M'))
            was_error = true;
        else {
            v.push_back(m.find(buff)->second);
            buff = inp[i];

        }
        i++;
    }
    if (m.count(buff))
        v.push_back(m.find(buff)->second);
    int s = 0;
    int prev_number = 10000;
    for (int i : v) {
        if (to_string(i).length() < to_string(prev_number).length()) {
            s += i;
            prev_number = i;
        }
        else {
            was_error = true;
        }
    }
    if (was_error)
        cout << "Ошибка";
    else
        cout << s;
}


## 7
// hw4_task7.cpp : Этот файл содержит функцию "main". Здесь начинается и заканчивается выполнение программы.
//

#include <iostream>
using namespace std;
int main()
{
    long m, b, c, s0=0, s, idx;
    system("chcp 1251");
    cout << "m = ";
    cin >> m;
    cout << "b = ";
    cin >> b;
    cout << "c = ";
    cin >> c;
    cout << "i = ";
    cin >> idx;
    for (int i = 1; i < idx; i++) {
        s = (m * s0 + b) % c;
        s0 = s;
        cout << i << ") " << s << "\n";
    }


}

## 8

#include <iostream>
#include <fstream>
using namespace std;

int main()
{
    system("chcp 1251");
    ifstream fin("input.txt");
    int A[10][10];
    //cout << "Hello World!\n";
    int n, m;
    //cout << "Введите матрицу A"<<"\n";
    //cout << "m = ";
    fin >> m;
    //cout << "n = ";
    fin >> n;



    for (int i = 0; i < m; i++) {
        for (int j = 0; j < n; j++) {
            fin >> A[i][j];
        }
    }

    float B[10][10];
    int w, t;
    //cout << "Введите матрицу B" << "\n";
    //cout << "w = ";
    fin >> w;
    //cout << "t = ";
    fin >> t;

    for (int i = 0; i < w; i++) {
        for (int j = 0; j < t; j++) {
            fin >> B[i][j];
        }
    }

    float C[10][10];
    for (int i = 0; i < m; i++) {
        for (int j = 0; j < t; j++) {
            C[i][j] = 0;
            for (int q=0; q < n; q++) {
                C[i][j] += A[i][q] * B[q][j];
            }
        }
    }
    cout << "Матрица С\n";

    float s = 0;
    float s_com = 0;

    int mini_s = 0, mini_s_com = 0;
    int max_s = 0, max_s_com = 0;
    for (int i = 0; i < m; i++) {
        if (C[i][0] < C[mini_s][0])
            mini_s = i;
        if (C[i][0] > C[max_s][0])
            max_s = i;
        s += C[i][0];
    }
    cout << "1) " <<max_s+1<< " и " <<mini_s+1<<"\n";


    for (int i = 0; i < m; i++) {
        if (C[i][1] < C[mini_s_com][1])
            mini_s_com = i;
        if (C[i][1] > C[max_s_com][1])
            max_s_com = i;
        s_com += C[i][1];
    }
    cout << "1) " << max_s_com+1 << " и " << mini_s_com+1<<"\n";

    cout << "3) " << s<<"\n";
    cout << "4) " << s_com<<"\n";
    cout << "5) " << s_com+s<<"\n";



}


## 9


#include <iostream>
#include <string>


using namespace std;


string n_to_q(long n, long q) {
    string result="";
    if (n < q) {
        if (n < 10 && n >= 0)
            result += to_string(n);
        else
            result.push_back((char)(n + 55));
    }

    else {
        result = n_to_q(n / q, q);
        if (n%q < 10 && n%q >= 0)
            result += to_string(n%q);
        else
            result.push_back((char)(n%q + 55));
    }
    return result;
}

int main()
{

    long n, new_q, old_q;
    string input;
    system("chcp 1251");
    cout << "Задача «Системы счисления»\n";
    cout << "old_q = ";
    cin >> old_q;
    cout << "number = ";
    cin >> input;

    n = 0;

    for (char i: input) {
        n *= old_q;
        if (isdigit(i))
            n += ((int)(i - 48));
        else
            n += ((int)(toupper(i) - 55));
    }
    //cout << "n = "<<n<<"\n";
    cout << "new_q = ";
    cin >> new_q;
    cout << n_to_q(n, new_q)<<"\n";

}