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Add flake8-builtins to pre-commit and fix errors (#7105)

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Ignore `A003`

Co-authored-by: Christian Clauss <cclauss@me.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Dhruv Manilawala <dhruvmanila@gmail.com>
This commit is contained in:
Caeden
2022-10-13 15:23:59 +01:00
committed by GitHub
parent e661b98829
commit d5a9f649b8
31 changed files with 113 additions and 106 deletions
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6
dynamic_programming/optimal_binary_search_tree.py
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@ -104,7 +104,7 @@ def find_optimal_binary_search_tree(nodes):
dp = [[freqs[i] if i == j else 0 for j in range(n)] for i in range(n)]
# sum[i][j] stores the sum of key frequencies between i and j inclusive in nodes
# array
sum = [[freqs[i] if i == j else 0 for j in range(n)] for i in range(n)]
total = [[freqs[i] if i == j else 0 for j in range(n)] for i in range(n)]
# stores tree roots that will be used later for constructing binary search tree
root = [[i if i == j else 0 for j in range(n)] for i in range(n)]
@ -113,14 +113,14 @@ def find_optimal_binary_search_tree(nodes):
j = i + interval_length - 1
dp[i][j] = sys.maxsize # set the value to "infinity"
sum[i][j] = sum[i][j - 1] + freqs[j]
total[i][j] = total[i][j - 1] + freqs[j]
# Apply Knuth's optimization
# Loop without optimization: for r in range(i, j + 1):
for r in range(root[i][j - 1], root[i + 1][j] + 1): # r is a temporal root
left = dp[i][r - 1] if r != i else 0 # optimal cost for left subtree
right = dp[r + 1][j] if r != j else 0 # optimal cost for right subtree
cost = left + sum[i][j] + right
cost = left + total[i][j] + right
if dp[i][j] > cost:
dp[i][j] = cost