message: Update last-day-where-you-can-still-cross.py
diff: @@ -47,7 +47,6 @@ class Solution(object):
  for i in reversed(xrange(len(cells))):
  r, c = cells[i]
  r, c = r-1, c-1
  - lookup[r][c] = True
  for dr, dc in directions:
  nr, nc = r+dr, c+dc
  if not (0 <= nr < row and 0 <= nc < col and lookup[nr][nc]):
  @@ -59,4 +58,5 @@ class Solution(object):
  uf.union_set(end, index(col, r, c))
  if uf.find_set(start) == uf.find_set(end):
  return i
  + lookup[r][c] = True
  return -1
  