solve spiral matrix

Author: sora0319

spiral-matrix/sora0319.java

@@ -0,0 +1,42 @@
+import java.util.*;
+
+class SolutionSpiral {
+    public List<Integer> spiralOrder(int[][] matrix) {
+        List<Integer> result = new ArrayList<>();
+
+        if (matrix == null || matrix.length == 0) return result;
+
+        int top = 0, bottom = matrix.length - 1;
+        int left = 0, right = matrix[0].length - 1;
+
+        while (top <= bottom && left <= right) {
+            // Traverse from left to right
+            for (int col = left; col <= right; col++) {
+                result.add(matrix[top][col]);
+            }
+            top++;
+
+            if (top > bottom) break;
+
+            for (int row = top; row <= bottom; row++) {
+                result.add(matrix[row][right]);
+            }
+            right--;
+
+            if (left > right) break;
+
+            for (int col = right; col >= left; col--) {
+                result.add(matrix[bottom][col]);
+            }
+            bottom--;
+
+            for (int row = bottom; row >= top; row--) {
+                result.add(matrix[row][left]);
+            }
+            left++;
+        }
+
+        return result;
+    }
+}
+