Merge pull request #557 from Ojasvix20/feat/hacktober/Spiral-Traversal

Added matrix Spiral Traversal Algorithm for hacktoberFest

Author: Pradeepsingh61

Java/algorithms/matrix/SpiralMatrixTraversal.java

@@ -0,0 +1,97 @@
+/*
+ * Algorithm Name: Spiral Matrix Traversal
+ * Programming Language: Java
+ * Category: Matrix
+ * Difficulty Level: Medium
+ *
+ * Author: Ojasvi Bakshi
+ *
+ * Algorithm Description:
+ * Given an m x n matrix, return all elements of the matrix in spiral order.
+ * The traversal starts from the top-left corner and moves layer by layer towards the center.
+ *
+ * Time Complexity: O(m*n) - Every element is visited exactly once.
+ * Space Complexity: O(m*n) - To store the resulting list. O(1) if printing directly.
+ */
+
+import java.util.Scanner;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Arrays;
+
+public class SpiralMatrixTraversal {
+
+    public static List<Integer> spiralOrder(int[][] matrix) {
+        List<Integer> result = new ArrayList<>();
+        if (matrix == null || matrix.length == 0) {
+            return result;
+        }
+
+        int m = matrix.length;
+        int n = matrix[0].length;
+        int top = 0, bottom = m - 1;
+        int left = 0, right = n - 1;
+
+        while (top <= bottom && left <= right) {
+            // 1. Traverse Right on the top row
+            for (int j = left; j <= right; j++) {
+                result.add(matrix[top][j]);
+            }
+            top++;
+
+            // 2. Traverse Down on the right column
+            for (int i = top; i <= bottom; i++) {
+                result.add(matrix[i][right]);
+            }
+            right--;
+
+            // 3. Traverse Left on the bottom row (check boundary)
+            if (top <= bottom) {
+                for (int j = right; j >= left; j--) {
+                    result.add(matrix[bottom][j]);
+                }
+                bottom--;
+            }
+
+            // 4. Traverse Up on the left column (check boundary)
+            if (left <= right) {
+                for (int i = bottom; i >= top; i--) {
+                    result.add(matrix[i][left]);
+                }
+                left++;
+            }
+        }
+        return result;
+    }
+
+    public static void main(String[] args) {
+        Scanner sc = new Scanner(System.in);
+
+        System.out.print("Enter number of rows: ");
+        int m = sc.nextInt();
+        System.out.print("Enter number of columns: ");
+        int n = sc.nextInt();
+
+        int[][] matrix = new int[m][n];
+
+        System.out.println("Enter matrix elements:");
+        for (int i = 0; i < m; i++) {
+            for (int j = 0; j < n; j++) {
+                matrix[i][j] = sc.nextInt();
+            }
+        }
+
+        System.out.println("\nOriginal Matrix:");
+        for (int[] row : matrix) {
+            System.out.println(Arrays.toString(row));
+        }
+
+        // Apply the algorithm
+        List<Integer> spiral = spiralOrder(matrix);
+
+        System.out.println("\nMatrix in Spiral Order:");
+        System.out.println(spiral);
+
+        sc.close();
+    }
+}