54 lines
1.2 KiB
Python
54 lines
1.2 KiB
Python
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from functools import cache
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import bisect
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import sys
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base_limit = sys.getrecursionlimit()
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def sc(cons):
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return (cons*(cons+1))/2
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def brutetop(a, b, k):
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first = {}
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for i in range(len(a)):
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if a[i] not in first and a[i] != b[i]:
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first[a[i]] = i
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@cache
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def brute(Q, i, cons):
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if i == len(a):
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return sc(cons)
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if a[i] == b[i] or a[i] in Q:
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return brute(Q, i+1, cons+1)
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if len(Q) < k and (a[i] in first and i == first[a[i]]):
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Qcop = list(Q)
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bisect.insort(Qcop, a[i])
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res1 = brute(Q, i+1, 0) + sc(cons)
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res2 = brute(tuple(Qcop), i+1, cons+1)
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return max(res1, res2)
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return brute(Q, i+1, 0) + sc(cons)
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return brute((), 0, 0)
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def main():
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ct = int(input())
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ress = []
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for _ in range(ct):
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# len(a, b), char lim
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n, k = [int(i) for i in input().split()]
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a = input() # a = base string
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b = input() # b = objective
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sys.setrecursionlimit(max(len(a), base_limit))
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print(int(brutetop(a, b, k)))
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#ress.append(str(int(brutetop(a, b, k))))
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#print("\n".join(ress))
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main()
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