标签：img har for out nbsp backtrack ice char enc
A permutation, also called an “arrangement number” or “order,” is a rearrangement of the elements of an ordered list S into a one-to-one correspondence with S itself. A string of length n has n! permutation.
Source: Mathword(http://mathworld.wolfram.com/Permutation.html)
Below are the permutations of string ABC.
ABC ACB BAC BCA CBA CAB
Here is a solution that is used as a basis in backtracking.
Solution:
class Main { public static void main(String[] args) { String str = "ABC"; Main m = new Main(); m.Permute(str,0,str.length()-1); } public void Permute(String str, int i, int j ){ if(i==j){ System.out.println(str); } else{ for(int l = i; l<=j; l++){ str = swap(str,i,l); Permute(str, i+1, j); str = swap(str,l,i); } } } public String swap(String a, int i, int j) { char temp; char[] charArray = a.toCharArray(); temp = charArray[i] ; charArray[i] = charArray[j]; charArray[j] = temp; return String.valueOf(charArray); } }
(Easy) BackTracking Permutations- Algorithm
标签：img har for out nbsp backtrack ice char enc
原文地址：https://www.cnblogs.com/codingyangmao/p/11436243.html
