Init

.gitignore

@@ -0,0 +1 @@
+*.class

App.java

@@ -0,0 +1,34 @@
+public class App {
+	private static final int WIDTH = 81;
+	private static final int HEIGHT = 5;
+	private static char[][] lines;
+	static {
+		lines = new char[HEIGHT][WIDTH];
+		for (int i = 0; i < HEIGHT; i++) {
+			for (int j = 0; j < WIDTH; j++) {
+				lines[i][j] = '*';
+			}
+		}
+	}
+
+	private static void show(int start, int len, int index) {
+		int seg = len / 3;
+		if (seg == 0) return;
+		for (int i = index; i < HEIGHT; i++) {
+			for (int j = start + seg; j < start + seg * 2; j++) {
+				lines[i][j] = ' ';
+			}
+		}
+		show(start, seg, index + 1);
+		show(start + seg * 2, seg, index + 1);
+	}
+	public static void main(String[] args) {
+		show(0, WIDTH, 1);
+		for (int i = 0; 1 < HEIGHT; i++) {
+			for (int j = 0; j < WIDTH; j++) {
+				System.out.print(lines[i][j]);
+			}
+			System.out.println();
+		}
+	}
+}

Calculations.java

@@ -0,0 +1,31 @@
+import java.util.function.Predicate;
+
+public class Calculations {
+	public static void main(String[] args) {
+		char[] chars = {'a', 'b', 'c', 'd'};
+		// поиск bba
+		calculate(chars, 3, i -> i[0] == 1 && i[1] == 1 && i[2] == 0);
+	}
+	static void calculate(char[] a, int k, Predicate<int[]> decider) {
+		int n = a.length;
+		if (k < 1 || k > n)
+			throw new IllegalArgumentException("Forbidden");
+		int[] indexes = new int[n];
+		int total = (int) Math.pow(n, k);
+		while (total-- > 0) {
+			for (int i = 0; i < n - (n - k) ; i++)
+				System.out.print(a[indexes[i]]);
+			System.out.println();
+			if (decider.test(indexes) )
+				break;
+			for (int i=0; i < n; i++) {
+				if (indexes[i] >= n - 1) {
+					indexes[i] = 0;
+				} else {
+					indexes[i]++;
+					break;
+				}
+			}
+		}
+	}
+}