Fix Windows compilation issue by adding malloc.h include

similarity_search.c

@@ -5,6 +5,11 @@
 #include <ctype.h>
 #include <math.h>
 #include <stdbool.h>
+#ifdef _WIN32
+#include <malloc.h>  // For alloca on Windows
+#else
+#include <alloca.h>  // For alloca on Unix-like systems
+#endif
 #include "similarity_search.h"
 
 // Case insensitive string comparison