diff --git a/cpp/exercises/practice/spiral-matrix/spiral_matrix.cpp b/cpp/exercises/practice/spiral-matrix/spiral_matrix.cpp
index 3428b39..603604b 100644
--- a/cpp/exercises/practice/spiral-matrix/spiral_matrix.cpp
+++ b/cpp/exercises/practice/spiral-matrix/spiral_matrix.cpp
@@ -2,4 +2,43 @@
 
 namespace spiral_matrix {
 
+     std::vector<std::vector<uint32_t>> spiral_matrix(uint32_t size) {
+        std::vector<std::vector<uint32_t>> matrix(size, std::vector<uint32_t>(size, 0));
+
+        if (size == 0)
+            return matrix;
+
+        uint32_t num = 1;
+        int top = 0, bottom = size - 1;
+        int left = 0, right = size - 1;
+
+        while (top <= bottom && left <= right) {
+            // move right
+            for (int col = left; col <= right; ++col)
+                matrix[top][col] = num++;
+            ++top;
+
+            // move down
+            for (int row = top; row <= bottom; ++row)
+                matrix[row][right] = num++;
+            --right;
+
+            // move left
+            if (top <= bottom) {
+                for (int col = right; col >= left; --col)
+                    matrix[bottom][col] = num++;
+                --bottom;
+            }
+
+            // move up
+            if (left <= right) {
+                for (int row = bottom; row >= top; --row)
+                    matrix[row][left] = num++;
+                ++left;
+            }
+        }
+
+        return matrix;
+    }
+
 }  // namespace spiral_matrix
diff --git a/cpp/exercises/practice/spiral-matrix/spiral_matrix.h b/cpp/exercises/practice/spiral-matrix/spiral_matrix.h
index cc56ad3..9c080f4 100644
--- a/cpp/exercises/practice/spiral-matrix/spiral_matrix.h
+++ b/cpp/exercises/practice/spiral-matrix/spiral_matrix.h
@@ -1,8 +1,11 @@
-#if !defined(SPIRAL_MATRIX_H)
+#ifndef SPIRAL_MATRIX_H
 #define SPIRAL_MATRIX_H
 
-namespace spiral_matrix {
+#include <vector>
+#include <cstdint>
 
+namespace spiral_matrix {
+    std::vector<std::vector<uint32_t>> spiral_matrix(uint32_t size);
 }  // namespace spiral_matrix
 
 #endif  // SPIRAL_MATRIX_H