Draft the priority queue

1 files changed, 2 insertions, 0 deletions

diff --git a/structs.h b/structs.h
index a82975d..5221829 100644
--- a/structs.h
+++ b/structs.h
@@ -1,6 +1,8 @@
 #ifndef STRUCTS_H_
 #define STRUCTS_H_
 
+#include <stddef.h>
+
 struct Position_s {
     size_t x;
     size_t y;