update

[M]dynamic-programming/[M]dynamic-programming/410-split-array-largest-sum.py

@@ -6,42 +6,39 @@ def splitArray(self, nums: List[int], k: int) -> int:
  for i, num in enumerate(nums):
  total += num
  prefix[i + 1] = total
- dp = [[float('inf')] * (k + 1) for _ in range(n)]
- for i in range(n):
- dp[i][1] = prefix[i + 1] - prefix[0]
 
+ dp = [[float('inf') for _ in range(k + 1)] for _ in range(n)]
+ for end in range(n):
+ dp[end][1] = prefix[end + 1] - prefix[0]
+
  for end in range(n):
  for interval in range(2, k + 1):
  for cut in range(end, interval - 2, - 1):
- cur_res = max(dp[cut - 1][interval - 1], prefix[end + 1] - prefix[cut])
- dp[end][interval] = min(dp[end][interval], cur_res)
-
+ largest_sum = max(dp[cut - 1][interval - 1], prefix[end + 1] - prefix[cut])
+ dp[end][interval] = min(dp[end][interval], largest_sum)
  return dp[n - 1][k]
 
-# time O(n** 2 * k)
+# time O(n**2 * k)
 # space O(nk)
 # using dynamic programming and interval (start from one interval)
 
 class Solution:
  def splitArray(self, nums: List[int], k: int) -> int:
 
- def valid(limit):
+ def valid(bound):
+ group = 1
  total = 0
- group = 0
  for num in nums:
- if num > limit:
+ if num > bound:
  return False
- if total + num <= limit:
- total += num
- else:
+ if total + num > bound:
  group += 1
  total = num
- if total:
- group += 1
+  else:
+  total += num
  return group <= k
 
- total = sum(nums)
- left, right, boundary = 0, total, - 1
+ left, right, boundary = 0, sum(nums), - 1
  while left <= right:
  m = (left + right) // 2
  if valid(m):