permutation

问题 Assume we have the following permutations of the letters, "a", "b", and "c": library(combinat) do.call(rbind, permn(letters[1:3])) # [,1] [,2] [,3] # [1,] "a" "b" "c" # [2,] "a" "c" "b" # [3,] "c" "a" "b" # [4,] "c" "b" "a" # [5,] "b" "c" "a" # [6,] "b" "a" "c" Is it possible to perform some function on a given permutation "on-the-fly" (i.e., a particular row) without storing the result? That is, if the row == "a" "c" "b" or row == "b" "c" "a" , do not store the result. The desired result in

问题 i have a code that generates a permutation based on the inputs of 8 columns and concatenates the columns together. it works great so far but i came up with a problem. it works when more than 2 rows are filled. so if theres only one entry in row 10 for any of the columns from A-H it crashes. the rows are filled with A,B,C across all 8 columns, if column 8 only had A then it crashes I've also tried Set col1 = Range(Range("A10"), Range("A" & Rows.Count).End(xlUp)) instead of Set col1 = Range(

问题 Project Euler 24: What is the millionth lexicographic permutation of the digits 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9? What if repetitions are allowed? like 1111111111 , 1223344457 etc. How can I get millionth permutation where repetitions are also included in counting. And please note that input would still be the same. No repetitions in input. I want to generate all possible passwords of length 10. And passwords can contain repeated characters so I want my function to work for that too. Here is

问题 Bash can produce permutations (cartesian product): $ echo {1,2}{a,b} 1a 1b 2a 2b I would like to do something similar with a makefile. Here is an example makefile: all: 1a 1b 2a 2b I would like something like this if possible: NOV = 1 2 OSC = a b all: $(NOV)$(OSC) However when I use an example like that it just creates "1 2a b" instead of combining them. Is this possible? 回答1: No need for any complex loops or borrowing from shell. It is much simpler than that. $(foreach p, $(NOV), $(addprefix

问题 Bash can produce permutations (cartesian product): $ echo {1,2}{a,b} 1a 1b 2a 2b I would like to do something similar with a makefile. Here is an example makefile: all: 1a 1b 2a 2b I would like something like this if possible: NOV = 1 2 OSC = a b all: $(NOV)$(OSC) However when I use an example like that it just creates "1 2a b" instead of combining them. Is this possible? 回答1: No need for any complex loops or borrowing from shell. It is much simpler than that. $(foreach p, $(NOV), $(addprefix

问题 This question already has answers here : Closed 8 years ago . Possible Duplicate: Generating all permutations of a given string I have an array of arbitrary length in Java, and I would like to generate all possible permutations of them. The easy way to do this for a fixed length would be a series of nested for loops, but because the array is of unknown length, that is not an option here. Is there a straightforward way to accomplish this in Java? 回答1: Use a recursive function, instead of loops

问题 I have 5 strings, such as: "one", "two", "three", "four", and "five". I need to get all permutations of these strings. I've explored all internet resources, but all solutions are so bulky and it's hard for me to understand it and integrate it to my program. So, maybe you know any easy solution how to get permutations. 回答1: Permutations are very easy to do. /// <summary> /// Returns all permutations of the input <see cref="IEnumerable{T}"/>. /// </summary> /// <param name="source">The list of

问题 I have 5 strings, such as: "one", "two", "three", "four", and "five". I need to get all permutations of these strings. I've explored all internet resources, but all solutions are so bulky and it's hard for me to understand it and integrate it to my program. So, maybe you know any easy solution how to get permutations. 回答1: Permutations are very easy to do. /// <summary> /// Returns all permutations of the input <see cref="IEnumerable{T}"/>. /// </summary> /// <param name="source">The list of

问题 I'm want to write function that returns next permutation in lexicographic order n choose k. So far I found following algorithm class Permutation { public function swap(& $a, $first, $second) { $tmp = $a[$first]; $a[$first] = $a[$second]; $a[$second] = $tmp; } function nextPermutation(& $a, $n, $k) { do { $first = $n - 2; while ($first != -1 && $a[$first] >= $a[$first + 1]) $first--; if ($first == -1) return false; $second = $n - 1; while ($a[$first] >= $a[$second]) $second--; $this->swap($a,

问题 I'm want to write function that returns next permutation in lexicographic order n choose k. So far I found following algorithm class Permutation { public function swap(& $a, $first, $second) { $tmp = $a[$first]; $a[$first] = $a[$second]; $a[$second] = $tmp; } function nextPermutation(& $a, $n, $k) { do { $first = $n - 2; while ($first != -1 && $a[$first] >= $a[$first + 1]) $first--; if ($first == -1) return false; $second = $n - 1; while ($a[$first] >= $a[$second]) $second--; $this->swap($a,