Initial Traverse array task

Author: ModestJean

src/II/_2_Traverce/Solver.java

@@ -0,0 +1,82 @@
+package II._2_Traverce;
+
+public class Solver {
+    static int n = 5;
+    static int curr = 1;
+    static int[][] array = new int[n+2][n+2];
+
+    public static void main() {
+        traverseFirstWay(0,1,1);
+        printMatrix();
+        System.out.println();
+
+        traverseSecondWay(1,1);
+        printMatrix();
+        System.out.println();
+
+        traverseThirdWay(1);
+        printMatrix();
+        System.out.println();
+    }
+
+    public static void printMatrix() {
+        for (int i = 1; i <= n; i++,System.out.println())
+            for (int j = 1; j <= n; j++)
+                System.out.printf("%3d",array[i][j]);
+    }
+
+    public static void traverseFirstWay(int line, int i, int j) {
+        int ii,jj;
+        int d = n - (int)Math.round((float)line / 2 + 0.25);
+        if (d == 0) return;
+        switch (line % 4) {
+            case 0:
+                for (jj = j; jj < j + d; jj++) array[i][jj] = curr++;
+                traverseFirstWay(++line, ++i, --jj); break;
+            case 1:
+                for (ii = i; ii < i + d; ii++) array[ii][j] = curr++;
+                traverseFirstWay(++line,--ii,--j); break;
+            case 2:
+                for (jj = j; jj > j - d; jj--) array[i][jj] = curr++;
+                traverseFirstWay(++line,--i,++jj); break;
+            case 3:
+                for (ii = i; ii > i - d; ii--) array[ii][j] = curr++;
+                traverseFirstWay(++line, ++ii, ++j); break;
+        }
+    }
+
+    public static void traverseSecondWay(int row, int col) {
+        array[col][row] = curr++;
+        if (row == n && col == n) return;
+
+        if ((row + col) % 2 == 0)
+            if (row == n)
+                traverseSecondWay(row, ++col); // right
+            else
+                if (col == 1)
+                    traverseSecondWay(++row, col); // down
+                else
+                    traverseSecondWay(++row, --col); // down left
+        else
+            if (col == n)
+                traverseSecondWay(++row, col); // down
+            else
+                if (row == 1)
+                    traverseSecondWay(row, ++col); // right
+                else
+                    traverseSecondWay(--row, ++col); // up right
+    }
+
+    public static void traverseThirdWay(int count) {
+        if (count > n) return;
+        else
+            if (count % 2 == 0) {
+                for (int i = n; i > 0; i--) array[i][count] = curr++;
+                traverseThirdWay(++count);
+            }
+            else {
+                for (int i = 1; i <= n; i++) array[i][count] = curr++;
+                traverseThirdWay(++count);
+            }
+    }
+}

src/Main.java

@@ -1,61 +1,11 @@
-import java.util.Collections;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.stream.Collectors;
-
-import static java.lang.System.out;
-
 public class Main {
 
     public static void main(String[] args) {
-        // Task A - create an array
-        int[] array = new int[] {5,2,1,4,2,3};
-
-        // Task B - create List, based on the array created above
-        List<Integer> list = new LinkedList<>();
-        for (int num: array)
-            Collections.addAll(list,num);
-        printList("Initial list:",list);
-
-        // C - sort ascending
-        Collections.sort(list);
-        printList("Sorted ascending:",list);
-
-        // D - sort descending
-        Collections.sort(list, (n1, n2) -> n2 - n1);
-        printList("Sorted descending:",list);
-
-        // Task E - shuffle
-        Collections.shuffle(list);
-        printList("Shuffled:",list);
-
-        // Task F - cyclic shirt
-        Collections.rotate(list,1);
-        printList("Shifted:",list);
-
-        // Task G - unique only
-        list = list.stream().distinct().collect(Collectors.toList());
-        printList("Distinct:",list);
-
-        // Task H - duplicates only
-        // Firstly, Add few duplicates
-        Collections.addAll(list,2,2,2,3,3,5);
-        // Secondly, remove unique
-        List<Integer> finalList = list;
-        list = list.stream().filter(elem -> finalList.lastIndexOf(elem) > finalList.indexOf(elem)).collect(Collectors.toList());
-        printList("Duplicates only:",list);
-
-        // Task I - convert list to array
-        Integer[] finalArray = list.stream().toArray(Integer[]::new);
-        out.print("The final array: ");
-        for (Integer num : finalArray)
-            out.print(num + " ");
-    }
+        II._1_Pascal.Solver.main();
+        II._2_Traverce.Solver.main();
 
-    private static void printList(String task, List<Integer> list) {
-        out.print(task + " ");
-        for(Integer number : list)
-            out.print(number + " ");
-        out.println();
+        III._1_Collections.Solver.main();
+        III._2_Primes.Solver.main();
+        III._3_Comparator.Solver.main();
     }
 }