2021 d5: fix typo error in solution code

Author: mebeim

2021/README.md

@@ -882,13 +882,13 @@ for points in starmap(diag, lines):
 Coupling this with `chain()` we can compress the double `for` into a single one:
 
 ```python
-for p in chain(starmap(horiz, lines)):
+for p in chain(*starmap(horiz, lines)):
     space[p] += 1
 
 overlapping = sum(x > 1 for x in space.values())
 print('Part 1:' overlapping)
 
-for p in chain(starmap(diag, lines)):
+for p in chain(*starmap(diag, lines)):
     space[p] += 1
 
 overlapping = sum(x > 1 for x in space.values())

2021/solutions/day05.py

@@ -33,14 +33,14 @@ def diag(ax, ay, bx, by):
 	bx, by = map(int, b.split(','))
 	lines.append((ax, ay, bx, by))
 
-for p in chain(starmap(horiz, lines)):
+for p in chain(*starmap(horiz, lines)):
 	space[p] += 1
 
 overlapping = sum(x > 1 for x in space.values())
 advent.print_answer(1, overlapping)
 
 
-for p in chain(starmap(diag, lines)):
+for p in chain(*starmap(diag, lines)):
 	space[p] += 1
 
 overlapping = sum(x > 1 for x in space.values())