Completed Array-1

spiralOrder.cpp

@@ -0,0 +1,51 @@
+ class Solution {
+public:
+    vector<int> spiralOrder(vector<vector<int>>& matrix) {
+
+        int m = matrix.size();
+        int n = matrix[0].size();
+        // top    → first row not yet printed
+        // bottom → last row not yet printed
+        // left   → first column not yet printed
+        // right  → last column not yet printed
+        int top = 0, bottom = m - 1, left = 0, right = n - 1;
+        vector<int> result;
+        while (top <= bottom && left <= right) {
+
+            // move left → right on the top row
+            for (int i = left; i <= right; i++) {
+                result.push_back(matrix[top][i]);
+            }
+            // top row is fully used, so move top boundary down
+            top++;
+
+            // move top → bottom on the right column
+            for (int i = top; i <= bottom; i++) {
+                result.push_back(matrix[i][right]);
+            }
+            // right column is done, so move right boundary left
+            right--;
+
+            // move right → left on the bottom row
+            // only if there are still rows left
+            if (top <= bottom) {
+                for (int i = right; i >= left; i--) {
+                    result.push_back(matrix[bottom][i]);
+                }
+                // bottom row is done, move bottom boundary up
+                bottom--;
+            }
+
+            // move bottom → top on the left column
+            // only if there are still columns left
+            if (left <= right) {
+                for (int i = bottom; i >= top; i--) {
+                    result.push_back(matrix[i][left]);
+                }
+                // left column is done, move left boundary right
+                left++;
+            }
+        }
+        return result;
+    }
+};