Update maximum-trailing-zeros-in-a-cornered-path.py

Author: kamyu104

Python/maximum-trailing-zeros-in-a-cornered-path.py

@@ -11,39 +11,36 @@ def maxTrailingZeros(self, grid):
         :type grid: List[List[int]]
         :rtype: int
         """
-        def factor(x, lookup):
-            if x not in lookup:
-                cnt = [0]*2
-                y = x
-                for i, p in enumerate([2, 5]):
-                    while y and y%p == 0:
-                        y //= p
-                        cnt[i] += 1
-                lookup[x] = cnt
-            return lookup[x]
+        def factor(x):
+            cnt = [0]*2
+            y = x
+            for i, p in enumerate([2, 5]):
+                while y and y%p == 0:
+                    y //= p
+                    cnt[i] += 1
+            return cnt
 
         def add(a, b):
             return [x+y for x, y in itertools.izip(a, b)]
 
         def sub(a, b):
             return [x-y for x, y in itertools.izip(a, b)]
 
-        lookup = {}
         left = [[None for _ in xrange(len(grid[0]))] for _ in xrange(len(grid))]
         for i in xrange(len(grid)):
-            left[i][0] = factor(grid[i][0], lookup)
+            left[i][0] = factor(grid[i][0])
             for j in xrange(1, len(grid[0])):
-                left[i][j] = add(left[i][j-1], factor(grid[i][j], lookup))
+                left[i][j] = add(left[i][j-1], factor(grid[i][j]))
         result = 0
         for j in xrange(len(grid[0])):
             total = [0]*2
             for i in xrange(len(grid)):
-                total = add(total, factor(grid[i][j], lookup))
+                total = add(total, factor(grid[i][j]))
             up = [0]*2
             for i in xrange(len(grid)):
                 right = sub(left[i][-1], left[i][j-1] if j else [0]*2)
                 result = max(result, min(add(left[i][j], up)), min(add(right, up)))
-                up = add(up, factor(grid[i][j], lookup))
+                up = add(up, factor(grid[i][j]))
                 down = sub(total, up)
                 result = max(result, min(add(left[i][j], down)), min(add(right, down)))
         return result