Created
February 18, 2019 07:38
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Reverse Burrows Wheeler Transformation
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| #include <iostream> | |
| #include <vector> | |
| #include <algorithm> | |
| #include <cassert> | |
| bool sortFunction(std::string s1, std::string s2){ | |
| if(s1[0] < s2[0]) return true; | |
| if(s2[0] < s1[0]) return false; | |
| int i = 0; | |
| int min = s1.size() < s2.size() ? s1.size() : s2.size(); | |
| bool isMinS1 = (min == s1.size()); | |
| bool isMinS2 = (min == s2.size()); | |
| for(i = 1; i<min; i++){ | |
| if(s1[i] < s2[i]) return true; | |
| if(s2[i] < s1[i]) return false; | |
| } | |
| if(isMinS1) return true; | |
| else if(isMinS2) return false; | |
| else return false; | |
| } | |
| void rotateStringsToRight(std::vector<std::string> &stringArray){ | |
| for(int i=0; i<stringArray.size(); i++){ | |
| std::string &x = stringArray[i]; | |
| x = x + x[x.size() - 1]; | |
| for(int j= x.size() -1; j>=0; j--){ | |
| x[j] = x[j-1]; | |
| } | |
| x[0] = '^'; | |
| } | |
| } | |
| void prependToBegin(std::vector<std::string> &stringArray, const std::string &toPrepend){ | |
| assert(stringArray.size() == toPrepend.size() && "Arrays need to have the same sizes."); | |
| for(int i=0; i<stringArray.size(); i++){ | |
| stringArray[i][0] = toPrepend[i]; | |
| } | |
| } | |
| int main(void){ | |
| std::string input; | |
| std::cin >> input; | |
| int index; | |
| std::cin >> index; | |
| std::vector<std::string> combinations; | |
| for(char ch: input) | |
| combinations.push_back(std::string(1, ch)); | |
| for(int x =1; x<input.size(); x++){ | |
| std::cout << "PASS # " << x << std::endl; | |
| std::cout << "-------------------" << std::endl; | |
| std::cout << "SORT: " << std::endl; | |
| std::sort(combinations.begin(), combinations.end(), sortFunction); | |
| for(std::string x: combinations){ | |
| std::cout << x << std::endl; | |
| } | |
| std::cout << "ROTATE: " << std::endl; | |
| rotateStringsToRight(combinations); | |
| std::sort(combinations.begin(), combinations.end(), sortFunction); | |
| for(std::string x: combinations){ | |
| std::cout << x << std::endl; | |
| } | |
| std::cout << "PREPEND: " << std::endl; | |
| prependToBegin(combinations, input); | |
| for(std::string x: combinations){ | |
| std::cout << x << std::endl; | |
| } | |
| std::cout << "-------------------" << std::endl; | |
| } | |
| // Final Sorting. | |
| std::sort(combinations.begin(), combinations.end(), sortFunction); | |
| std::cout << "Original String: " << combinations[index] << std::endl; | |
| return 0; | |
| } |
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