Fix memory initialisation bug in intcode

1 files changed, 1 insertions, 1 deletions

diff --git a/2019/IntCode.hs b/2019/IntCode.hs
index 1730dfd..0729e0f 100644
--- a/2019/IntCode.hs
+++ b/2019/IntCode.hs
@@ -149,7 +149,7 @@ runArray arr ptr inp offset = do
             (_, right) <- SA.getBounds arr1
             if idx < right
                 then return arr1
-                else SA.getElems arr1 >>= \els -> SA.newListArray (0, 2 * idx) (els ++ replicate (idx - right + 1) 0)
+                else SA.getElems arr1 >>= \els -> SA.newListArray (0, 2 * idx) (els ++ replicate (2 * idx - right) 0)
         performWrite arr1 idx value = do
             arr' <- resize arr1 (fromIntegral idx)
             SA.writeArray arr' (fromIntegral idx) value