diff --git a/.github/workflows/awesome_workflow.yml b/.github/workflows/awesome_workflow.yml index 225f659e1..d9b405ec2 100644 --- a/.github/workflows/awesome_workflow.yml +++ b/.github/workflows/awesome_workflow.yml @@ -21,8 +21,8 @@ jobs: # The default installs v6.0 which did not work out well in my tests - name: Setup Git Specs run: | - git config --global user.name github-actions - git config --global user.email '${GITHUB_ACTOR}@users.noreply.github.com' + git config --global user.name David Leal + git config --global user.email 'Panquesito7@users.noreply.github.com' git remote set-url origin https://x-access-token:${{ secrets.GITHUB_TOKEN }}@github.com/$GITHUB_REPOSITORY - name: Filename Formatter run: | diff --git a/DIRECTORY.md b/DIRECTORY.md index 392415722..8ec4e216a 100644 --- a/DIRECTORY.md +++ b/DIRECTORY.md @@ -1,6 +1,6 @@ ## Backtracking - * [Graph Coloring](https://github.com/TheAlgorithms/C-Plus-Plus/blob/master/backtracking/graph_coloring.cpp) + * [Graph Coloringg](https://github.com/TheAlgorithms/C-Plus-Plus/blob/master/backtracking/graph_coloringg.cpp) * [Knight Tour](https://github.com/TheAlgorithms/C-Plus-Plus/blob/master/backtracking/knight_tour.cpp) * [Magic Sequence](https://github.com/TheAlgorithms/C-Plus-Plus/blob/master/backtracking/magic_sequence.cpp) * [Minimax](https://github.com/TheAlgorithms/C-Plus-Plus/blob/master/backtracking/minimax.cpp) diff --git a/backtracking/graph_coloring.cpp b/backtracking/graph_coloringg.cpp similarity index 100% rename from backtracking/graph_coloring.cpp rename to backtracking/graph_coloringg.cpp diff --git a/search/interpolation_search.cpp b/search/interpolation_search.cpp index 4339dc366..5ed757749 100644 --- a/search/interpolation_search.cpp +++ b/search/interpolation_search.cpp @@ -1,61 +1,123 @@ -/** - * \file - * \brief [Interpolation - * search](https://en.wikipedia.org/wiki/Interpolation_search) algorithm - */ -#include -/** function to search the value in an array using interpolation search - * \param [in] arr array to search in - * \param [in] value value to search for - * \param [in] len length of array - * \returns index where the value is found - * \returns 0 if not found - */ -int interpolation_search(int arr[], int value, int len) { - int low = 0, high, mid; - high = len - 1; +/****************************************************************************** + * @file + * @brief [Interpolation search + * algorithm](https://en.wikipedia.org/wiki/interpolation_search) + * + * @details + * interpolation search resembles the method by which people search a telephone + * directory for a name (the key value by which the book's entries are ordered): + * in each step the algorithm calculates where in the remaining search space + * the sought item might be, based on the key values at the bounds of the search + * space and the value of the sought key, usually via a linear interpolation. + * The key value actually found at this estimated position is then compared to + * the key value being sought. If it is not equal, then depending on the + * comparison, the remaining search space is reduced to the part before or + * after the estimated position. This method will only work if calculations + * on the size of differences between key values are sensible. - while (arr[low] <= value && arr[high] >= value) { - mid = (low + - ((value - arr[low]) * (high - low)) / (arr[high] - arr[low])); - if (arr[mid] > value) - high = mid - 1; - else if (arr[mid] < value) - low = mid + 1; - else - return mid; + * ### Complexities + * + * //n is the number of element in the array. + * + * Worst-case time complexity O(n) (when items are distributed + exponentially) + * Average time complexity O(log2(log2 n)) + * space complexity 0(1) + * + * @author [Lajat Manekar](https://github.com/Lazeeez) + * @author Unknown author + *******************************************************************************/ + +#include /// for std::sort function +#include /// for std::assert +#include /// for IO operations +#include /// for std::vector + +/****************************************************************************** + * @namespace search + * @brief Searching algorithms + *******************************************************************************/ +namespace search { + +/****************************************************************************** + * @namespace interpolation_search + * @brief Functions for the [Interpolation + *Search](https://en.wikipedia.org/wiki/interpolation_search) algorithm + *implementation + *******************************************************************************/ +namespace interpolation_search { + +/****************************************************************************** + * @brief The main function which implements interpolation search + * @param arr vector to be searched in + * @param number value to be searched + * @returns integer index of `number` in vector `arr` + *******************************************************************************/ +uint64_t interpolationSearch(const std::vector &arr, + uint64_t number) { + uint64_t size = arr.size(); + uint64_t low = 0, high = (size - 1); + + // Since vector is sorted, an element present in array must be in range + // defined by corner + while (low <= high && number >= arr[low] && number <= arr[high]) { + if (low == high) { + if (arr[low] == number) { + return low; + } + return -1; + } + // Probing the position with keeping uniform distribution in mind. + uint64_t pos = + low + + ((static_cast(high - low) / (arr[high] - arr[low])) * + (number - arr[low])); + + if (arr[pos] == number) { + return pos; // Condition of target found + } + + if (arr[pos] < number) { + low = pos + 1; // If x is larger, x is in upper part + } + + else { + high = pos - 1; // If x is smaller, x is in the lower part + } } - - if (arr[low] == value) - return low; - return -1; } -/** main function */ +} // namespace interpolation_search + +} // namespace search + +/******************************************************************************* + * @brief Self-test implementation + * @returns void + *******************************************************************************/ +static void tests() { + // testcase + // array = [10, 12, 13, 16, 18, 19, 20, 21, 1, 2, 3, 4, 22, 23, 24, 33, 35, + // 42, 47] , Value = 33 should return 15 + std::vector arr = {{10, 12, 13, 16, 18, 19, 20, 21, 1, 2, 3, 4, + 22, 23, 24, 33, 35, 42, 47}}; + sort(arr.begin(), arr.end()); + uint64_t number = 33; // Element to be searched + uint64_t expected_answer = 15; + uint64_t derived_answer = + search::interpolation_search::interpolationSearch(arr, number); + std::cout << "Testcase: "; + assert(derived_answer == expected_answer); + std::cout << "Passed!\n"; +} + +/******************************************************************************* + * @brief Main function + * @returns 0 on exit + *******************************************************************************/ int main() { - int n, value, re; - - std::cout << "Enter the size of array(less than 100) : "; - std::cin >> n; - - int *array = new int[n]; - - std::cout << "array in ascending (increasing) order : " << std::endl; - - for (int i = 0; i < n; i++) std::cin >> array[i]; - - std::cout << "Enter the value you want to search : "; - std::cin >> value; - - re = interpolation_search(array, value, n); - - if (re == -1) - std::cout << "Entered value is not in the array" << std::endl; - else - std::cout << "The value is at the position " << re << std::endl; - - delete[] array; + tests(); // run self-test implementations return 0; }