import java.util.*; public class Main { public static void main(String[] args) { int[] numbs = { 1, 2, 3 }; int[] numbs2 = new int[3]; String[] strs = new String[] { "a", "b", "c" }; System.out.println(strs.length); // 3 int[] arr = new int[3]; arr[0]=10; System.out.println(arr.length); // 3 // Τ[] arrayname = new Τ[n]; int SIZE = 10; int[] bathmoi = new int[SIZE]; for (int i = 0; i < SIZE; i++) bathmoi[i] = i+10; int bathmos = bathmoi[1]; // 2ο στοιχείο System.out.println(bathmos); // 11 bathmoi[5] = 18; int key = 20; int index = Arrays.binarySearch(bathmoi, key); System.out.println(index); // -11 Arrays.sort(bathmoi); System.out.println(bathmoi.length); //10 int[] b=Arrays.copyOfRange(bathmoi, 0, SIZE); System.out.println(b.length); // 10 // Τ[][] arrayname = new Τ[m][n]; //int m = 2, n = 3; //int[][] matrix = new int[m][n]; int[][] numbers = { { 1, 2, 3 }, { 4, 5, 6 } }; System.out.println(Arrays.deepToString(numbers)); int[][] numbers2 = new int[2][3]; System.out.println(Arrays.deepToString(numbers2)); numbers2[0][1] = 6; System.out.println(Arrays.deepToString(numbers2)); int[][] a = { {1}, {2, 3}, null }; // πίνακας με γραμμές διαφόρων μεγεθών (ragged table) System.out.println(Arrays.deepToString(a)); System.out.println(a.length); System.out.println(Arrays.toString(a[0])); System.out.println(a[0].length); String[] strings = new String[3]; Arrays.fill(strings, "a"); System.out.println(Arrays.toString(strings)); Arrays.fill(strings, 1, 2, "b"); System.out.println(Arrays.toString(strings)); String[] strings_ = new String[3]; Arrays.fill(strings_, "a"); System.out.println(Arrays.toString(strings_)); System.out.println(Arrays.mismatch(strings, strings_)); System.out.println(Arrays.compare(strings, strings_)); int[] array = new int[10]; for (int i = 0; i < array.length; i++) { array[i] = i; } for (int e : array) { System.out.print(e + " "); } int[][] matrix = new int[5][5]; for (int i = 0; i < matrix.length; i++) { for (int j = 0; j < matrix[i].length; j++) { matrix[i][j] = i+j; } } for (int[] nums : matrix) { for (int e : nums) { System.out.print(e + " "); } System.out.println(); } int [] array1 = {1, 2, 3, 4, 5}; System.out.println(Arrays.toString(array1)); int[][] array2d = { {1, 2, 3}, {4, 5, 6}, {7, 8, 9} }; System.out.println(Arrays.deepToString(array2d)); int[] array2 = {2, 9, -1, 4, 13}; Arrays.sort(array2); // με αριθμητική σειρά System.out.println(Arrays.toString(array2)); String[] names = {"Κώστας", "Γιάννης", "Κατερίνα", "Μαρία", "Ανάργυρος"}; Arrays.sort(names, 0, names.length, Collections.reverseOrder()); // λεξικογραφικά System.out.println(Arrays.toString(names)); System.out.println(Arrays.binarySearch(array, 4)); // εύρεση του 4 int[] newArray = Arrays.copyOf(array, array.length+1); System.out.println(Arrays.toString(newArray)); newArray = Arrays.copyOfRange(array, 1, 2); System.out.println(Arrays.toString(newArray)); int[] clonedArray = array.clone(); System.out.println(Arrays.toString(clonedArray)); int[] array3 = new int[5]; System.arraycopy(array, 0, array3, 0, 5); System.out.println(Arrays.toString(array2)); newArray = new int[array.length-1]; index = 1; // θέλουμε να διαγράψουμε το 2ο στοιχείο System.arraycopy(array, 0, newArray, 0, index); System.out.println(Arrays.toString(newArray)); System.arraycopy(array, index + 1, newArray, index, array.length - index - 1); // αντιγραφή από array[index+1] μέχρι array[array.length-1]; System.out.println(Arrays.toString(newArray)); int[][] newArray2d = Arrays.copyOf(array2d, array2d.length+1); System.out.println(Arrays.equals(array, newArray)); System.out.println(Arrays.deepEquals(array2d, newArray2d)); // για n-διαστάσεις int[][] aa = { { 1, 2, 3 }, { 4, 5, 6 } }; int[][] bb = { { 4, 5 }, { 7, 8 }, { 1, 2 } }; int[][] cc = new int[aa.length][bb[0].length]; for (int row=0; row < aa.length; row++) { for (int col=0; col < bb[row].length; col++) { for (int i = 0; i < bb.length; i++) { cc[row][col] += aa[row][i] * bb[i][col]; } } } for (int i=0; i < cc.length; i++) { for (int j=0; j < cc[i].length; j++) { System.out.print(" | " + cc[i][j]); } System.out.println(" |"); } int[] d = {5, -7, 0, -1, 3, 12}; int[] p = new int[d.length]; // μπορεί όλα τα στοιχεία να 'ναι θετικοί ή μηδέν int[] n = new int[d.length]; // μπορεί όλα τα στοιχεία να 'ναι αρνητικοί int pi = 0, ni = 0; for (int e : d) { if (e >= 0) { p[pi++] = e; } else { n[ni++] = e; } } for (int i=0; i < pi; i++) { System.out.print(" " + p[i]); } System.out.println(); for (int i=0; i < ni; i++) { System.out.print(" " + n[i]); } } }