Laba2

src/Main.java

-//TIP To <b>Run</b> code, press <shortcut actionId="Run"/> or
-// click the <icon src="AllIcons.Actions.Execute"/> icon in the gutter.
+import java.util.Scanner;
 public class Main {
+
     public static void main(String[] args) {
-        int height = 100;
-        int width = 100;
-
-        int All = height * width;
-        double step = Math.PI / (All - 1);
-
-        double[][] table = new double[height][width];
-        double[][] table_x = new double[height][width];
-        double x = -step;
-        for (int i = 0; i < width; i++) {
-            for (int j = 0; j < height; j++) {
-                x += step;
-                table_x[j][i] = x;
-                table[j][i] = Math.abs(Math.sin(x));
+        Scanner scanner = new Scanner(System.in);
+
+        System.out.print("Введите коэффициенты a, b, c: ");
+        double a = scanner.nextDouble();
+        double b = scanner.nextDouble();
+        double c = scanner.nextDouble();
+
+        System.out.print("Введите границы интервала от и до: ");
+        double xfrom = scanner.nextDouble();
+        double xto = scanner.nextDouble();
+
+        System.out.print("Введите размер таблицы: ");
+        int tableSize = scanner.nextInt();
+
+        System.out.print("Введите число разбиений отрезка: ");
+        int stepsCount = scanner.nextInt();
+
+        scanner.close();
+
+        String[][] table = buildTable(a, b, c, xfrom, xto, tableSize, stepsCount);
+        printTable(table);
+    }
+
+    public static double f(double a, double b, double c, double x) {
+        return a * x * x + b * x + c;
+    }
+
+    public static double integral(double a, double b, double c, double x0, double x1, int steps) {
+        if (x0 > x1) return -integral(a, b, c, x1, x0, steps);
+
+        double n = (x1 - x0) / steps;
+        double sum = (f(a, b, c, x0) + f(a, b, c, x1));
+        for (int i = 1; i < steps; i++) {
+            double xi = x0 + i * n;
+            sum += 2 * f(a, b, c, xi);
+        }
+        return sum * n / 2;
+    }
+
+
+    public static String[][] buildTable(double a, double b, double c, double xfrom, double xto, int tableSize, int stepsCount) {
+        String[][] table = new String[tableSize + 1][tableSize + 1];
+        double[] xValues = new double[tableSize];
+        double step = (xto - xfrom) / (tableSize - 1);
+
+        for (int i = 0; i < tableSize; i++) {
+            xValues[i] = xfrom + i * step;
+            table[0][i + 1] = String.format("%.4f", xValues[i]);
+            table[i + 1][0] = String.format("%.4f", xValues[i]);
+        }
+        table[0][0] = " ";
+
+        for (int i = 1; i < tableSize + 1; i++) {
+            for (int j = 1; j < tableSize + 1; j++) {
+                double x0 = xValues[i - 1];
+                double x1 = xValues[j - 1];
+                table[i][j] = String.format("%.4f", integral(a, b, c, x0, x1, stepsCount));
             }
         }
+        return table;
+    }
 
-        for (int i = 0; i < height; i++) {
-            for (int j = 0; j < width; j++) {
-                double orig = Math.asin(table[i][j]);
-                System.out.printf("sin(%.4f)=%.4f   ", table_x[i][j], table[i][j]);
+    public static void printTable(String[][] table) {
+        int cnt = 0;
+        for (String[] row : table) {
+            String row1 = row[0];
+            System.out.printf("%10s |", row1);
+            for (int i = 1; i < row.length; i++) {
+                String cell = row[i];
+                System.out.printf("%10s", cell);
             }
             System.out.println();
+            cnt += 1;
+            if (cnt < row.length) {
+                System.out.print("-----------|");
+                for (int i = 1; i < row.length; i++) {
+                    System.out.print("----------");
+                }
+                System.out.println();
+            }
         }
     }
 }
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