add cstring

1 files changed, 1 insertions, 0 deletions

diff --git a/world.cpp b/world.cpp
index e99ce97..40c49ea 100644
--- a/world.cpp
+++ b/world.cpp
@@ -1,5 +1,6 @@
 #include <cstdlib>
 #include <cassert>
+#include <cstring>
 #include "world.h"
 
 using namespace std;