diff --git a/leetcode/problem_4/sol1.c b/leetcode/problem_4/sol1.c
index de676f44..9d11f366 100644
--- a/leetcode/problem_4/sol1.c
+++ b/leetcode/problem_4/sol1.c
@@ -1,11 +1,33 @@
+/**
+ * \file
+ * \brief [4. Median of two sorted
+ * arrays](https://leetcode.com/problems/median-of-two-sorted-arrays/) solution
+ * \details
+ * Given two sorted arrays `nums1` and `nums2` of size `m` and `n` respectively,
+ * return the median of the two sorted arrays.
+ */
 
+#include <assert.h>
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
 
-double findMedianSortedArrays(int *nums1, int nums1Size, int *nums2,
-                              int nums2Size)
+/**
+ * @brief Computes median of two sorted arrays
+ *
+ * @param nums1 sorted array 1
+ * @param nums1Size size of strted array 1
+ * @param nums2 sorted array 2
+ * @param nums2Size size of sorted array 2
+ * @return median of the two arrays
+ */
+double findMedianSortedArrays(int *nums1, size_t nums1Size, int *nums2,
+                              size_t nums2Size)
 {
+    double out;
     int index1 = 0;
     int index2 = 0;
-    int v[nums1Size + nums2Size];
+    int *v = (int *)malloc((nums1Size + nums2Size) * sizeof(int));
     int v_index = 0;
 
     while (index1 < nums1Size && index2 < nums2Size)
@@ -35,16 +57,48 @@ double findMedianSortedArrays(int *nums1, int nums1Size, int *nums2,
     }
     if (v_index == 1)
     {
-        return v[0];
+        out = v[0];
+        free(v);
+        return out;
     }
     if (v_index % 2 == 0)
     {
         double n1, n2;
-        n1 = v[v_index / 2];
-        n2 = v[(v_index / 2) - 1];
-        return (n1 + n2) / 2;
+        n1 = v[v_index >> 1];
+        n2 = v[(v_index >> 1) - 1];
+        out = (n1 + n2) / 2;
+        free(v);
+        return out;
     }
-    int new_index = (int)v_index / 2;
+    int new_index = (int)v_index >> 1;
     int i = 0;
-    return v[new_index];
+    out = v[new_index];
+    free(v);
+    return out;
+}
+
+/** Main function
+ * @returns 0
+ */
+int main()
+{
+    int array1[] = {1, 3};
+    int array2[] = {2};
+    double median1 = findMedianSortedArrays(array1, 2, array2, 1);
+    assert(fabs(median1 - 2.f) <= 0.01);
+    printf("Test 1 passed.\n");
+
+    int array3[] = {1, 2};
+    int array4[] = {3, 4};
+    double median2 = findMedianSortedArrays(array3, 2, array4, 2);
+    assert(fabs(median2 - 2.5f) <= 0.01);
+    printf("Test 2 passed.\n");
+
+    int array5[] = {0, 0};
+    int array6[] = {0, 0};
+    double median3 = findMedianSortedArrays(array5, 2, array6, 2);
+    assert(fabs(median3 - 0.f) <= 0.01);
+    printf("Test 3 passed.\n");
+
+    return 0;
 }