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FIX: levenshtein dist

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This commit is contained in:
WayneCui 2019-03-08 19:50:38 +08:00
parent a29336bcd9
commit 2961763cb2
1 changed files with 35 additions and 7 deletions
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42
python/42_dynamic_programming/min_edit_dist.py
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@ -4,13 +4,29 @@
def levenshtein_dp(s: str, t: str) -> int: def levenshtein_dp(s: str, t: str) -> int:
m, n = len(s), len(t) m, n = len(s), len(t)
table = [[0] * (n + 1) for _ in range(m + 1)] table = [[0] * (n) for _ in range(m)]
table[0] = [j for j in range(m + 1)]
for i in range(m + 1): for i in range(n):
table[i][0] = i if s[0] == t[i]:
for i in range(1, m + 1): table[0][i] = i - 0
for j in range(1, n + 1): elif i != 0:
table[i][j] = min(1 + table[i - 1][j], 1 + table[i][j - 1], int(s[i - 1] != t[j - 1]) + table[i - 1][j - 1]) table[0][i] = table[0][i - 1] + 1
else:
table[0][i] = 1
for i in range(m):
if s[i] == t[0]:
table[i][0] = i - 0
elif i != 0:
table[i][0] = table[i - 1][0] + 1
else:
table[i][0] = 1
for i in range(1, m):
for j in range(1, n):
table[i][j] = min(1 + table[i - 1][j], 1 + table[i][j - 1], int(s[i] != t[j]) + table[i - 1][j - 1])
print(table)
return table[-1][-1] return table[-1][-1]
@ -29,3 +45,15 @@ if __name__ == "__main__":
print(levenshtein_dp(s, t)) print(levenshtein_dp(s, t))
print(common_substring_dp(s, t)) print(common_substring_dp(s, t))
s = "kitten"
t = "sitting"
print(levenshtein_dp(s, t))
print(common_substring_dp(s, t))
s = "flaw"
t = "lawn"
print(levenshtein_dp(s, t))
print(common_substring_dp(s, t))