![]() That way, as the digit splitter is combined with the first character, it always results in just the first character. The binary string is an extra digit long so that the first digit is always ''. Str(a > i & 1) converts a into a binary string, which then has it's 0's and 1's replaced by '' and ' ', respectively. Example 1: Input: ABC Output: ABC ACB BAC BCA CAB CBA Explanation: Given string ABC has permutations in 6 forms as ABC, ACB, BAC, BCA, CAB and CBA. ![]() The task is to print all unique permutations of the given string in lexicographically sorted order. S_length = len(s)-1 # represents the number of ' ' or '' that can split digitsįor i in range(s_length, -1, -1)]) # extra digit is for blank string to always precede first digitįor a in range(pow(2, s_length)) # binary number loop Permutations of a given string Medium Accuracy: 34.65 Submissions: 230K+ Points: 4 Given a string S. ke y ('' between 'k' and 'e', ' ' between 'e' and 'y')Īn unreadable python one liner that gives you a generator in string form: operator_positions = (''.join( for i in range(len(s)-1, -1, -1)]) for a in range(pow(2, len(s)-1)))Ī readable version of this generator with comments and sample: s = 'monkey'.k e y (' ' between 'k' and 'e', ' ' between 'e' and 'y').k ey (' ' between 'k' and 'e', '' between 'e' and 'y'). ![]() key ('' between 'k' and 'e', '' between 'e' and 'y').That can be mapped to 1 and 0, and the number of possible splits are a power of 2:įor example, "key" can have '' or ' ' separating 'ke' and a '' or ' ' separating 'ey' which leads to 4 possibilities: Install via > pip install more_itertools.Ī string (as opposed to list) oriented approach is to think of the each adjacent pair of characters being separated by either a space or empty string. With this in mind, a simple algorithm can be implemented: > def permute(s):Īfter some string joining: Union of 1, 2, 3, and 4, yield all permutations of the string key.The idea is to realize that the permutation of a string s is equal to a set containing s itself, and a set union of each substring X of s with the permutation of s\X. Return for sl in map(slice, chain(b, d), chain(d, e))] ![]() Splits = (d for i in range(n) for d in combinations(mid, i)) '''Return a sliceable version of the iterable xs.''' Contains an interesting post about sequence partitioning, here is the implementation they use: #!/usr/bin/env pythonįrom itertools import chain, combinations ![]()
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