OOP_IO-2x_2023-mirror/lab1 fedoniuk

import java.util.Scanner;

public class lab1 {
    public static void main(String[] args) {
        int C2, C3, C5;
        var C7 = 0;

        Scanner id = new Scanner(System.in);
        System.out.print("Enter the student's ID number: ");
        int idbook = id.nextInt();

        C2 = idbook % 2;
        C3 = idbook % 3;
        C5 = idbook % 5;
        C7 = idbook % 7;

        String[] oper1 = {"+", "-"};
        String[] oper2 = {"*", "/", "%", "+", "-"};
        String[] oper3 = {"byte", "short", "int", "long", "char", "float", "double"};

        int C = C3;

        String O1 = oper1[C2];
        String O2 = oper2[C5];
        String O3 = oper3[C7];

        System.out.println("C2 is: " + C2 + ", operation is: " + O1);
        System.out.println("C3 = " + C);
        System.out.println("C5 is: " + C5 + ", operation is: " + O2);
        System.out.println("C7 is: " + C7 + ", Type of indexes i and j is: " + O3);

        double i = 0;
        double j = 0;
        System.out.println("\nEnter a values for lower limits (i and j) in the "+ O3+" type: ");
        switch (O3) {
            case "byte" -> {
                i = id.nextByte();
                j = id.nextByte();
            }
            case "short" -> {
                i = id.nextShort();
                j = id.nextShort();
            }
            case "int" -> {
                i = id.nextInt();
                j = id.nextInt();
            }
            case "long" -> {
                i = id.nextLong();
                j = id.nextLong();
            }
            case "char" -> {
                i = id.next().charAt(0);
                j = id.next().charAt(0);
            }
            case "float" -> {
                i = id.nextFloat();
                j = id.nextFloat();
            }
            case "double" -> {
                i = id.nextDouble();
                j = id.nextDouble();
            }
        }

        System.out.println("The value of the created variables is: " + i + " and " + j);
        System.out.println("Enter values for top limits (n and m):");
        int n, m;
        n = id.nextInt();
        m = id.nextInt();

        double sum = 0, res = 0, res2 = 0;

        if ((O1.equals("-") && i + n >= C && i <= C) || i > n || j > m || (C == 0 && i == 0)) {
            System.out.println("Incorrect input, try another values");
        } else {
            for (double a = i; a <= n; a++) {
                for (double b = j; b <= m; b++) {
                    switch (O1) {
                        case "+" -> res = a + C;
                        case "-" -> res = a - C;
                    }
                    switch (O2) {
                        case "+" -> res2 = a + b;
                        case "-" -> res2 = a - b;
                        case "*" -> res2 = a * b;
                        case "/" -> res2 = a / b;
                        case "%" -> res2 = a % b;
                    }
                    sum += res2 / res;
                }
            }
            System.out.println("Sum is: " + sum);
        }
    }
}