Main Exercise 2 completed.

src/main/java/MainExercises.java

@@ -1,8 +1,12 @@
+import java.util.Arrays;
+import java.util.ArrayList;
+
 public class MainExercises
 {
     public char[][] generateTriangle(int n) {
         char[][] Triangle = new char[n][];
 
+        //The for loop to put the stars a spaces in the array
         for(int i=0; i<n; i++) {
             Triangle[i] = new char[i+1];
             for (int j = 0; j <= i; j++) {
@@ -47,10 +51,51 @@ public class MainExercises
            - Number of columns: matrix[0].length (if rectangular)
    */
     public int[] spiralTraversal(int[][] matrix) {
-        // todo
-        return null;
+        ArrayList<Integer> result = new ArrayList<>();
+
+        //Setting matrix edge indices
+        int top = 0;
+        int bottom = matrix.length - 1;
+        int left = 0;
+        int right = matrix[0].length - 1;
+
+        //This loop reads the indices in a spiral order and at each stage, it brings the edges closer to the center.
+        while ((top <= bottom) && (left <= right)) {
+            for (int i=left; i <= right; i++) {
+                result.add(matrix[top][i]);
+            }
+            top++;      //to getting closer to the center
+
+            for (int i=top; i <= bottom; i++) {
+                result.add(matrix[i][right]);
+            }
+            right--;    //to getting closer to the center
+
+            if (top <= bottom) {
+                for (int i = right; i >= left; i--) {
+                    result.add(matrix[bottom][i]);
+                }
+                bottom--;
+            }
+
+            if (left <= right) {
+                for (int i = bottom; i >= top; i--) {
+                    result.add(matrix[i][left]);
+                }
+                left++;
+            }
+        }
+
+        int n = (matrix.length)*(matrix[0].length);
+        int[] finalResult = new int[n];    //for returning an int[] array
+        for (int i=0; i<n; i++) {
+            finalResult[i] = result.get(i);
+        }
+        return finalResult;
     }
 
+
+
     /*
         integer partitioning is a combinatorics problem in discreet maths
         the problem is to generate sum numbers which their summation is the input number