Merge branch 'master' into my-bit-contribution

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David Leal 2022-01-02 21:45:08 -06:00 committed by GitHub
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@ -21,8 +21,8 @@ jobs:
# The default installs v6.0 which did not work out well in my tests # The default installs v6.0 which did not work out well in my tests
- name: Setup Git Specs - name: Setup Git Specs
run: | run: |
git config --global user.name github-actions git config --global user.name David Leal
git config --global user.email '${GITHUB_ACTOR}@users.noreply.github.com' git config --global user.email 'Panquesito7@users.noreply.github.com'
git remote set-url origin https://x-access-token:${{ secrets.GITHUB_TOKEN }}@github.com/$GITHUB_REPOSITORY git remote set-url origin https://x-access-token:${{ secrets.GITHUB_TOKEN }}@github.com/$GITHUB_REPOSITORY
- name: Filename Formatter - name: Filename Formatter
run: | run: |

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## Backtracking ## 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) * [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) * [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) * [Minimax](https://github.com/TheAlgorithms/C-Plus-Plus/blob/master/backtracking/minimax.cpp)

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/**
* \file
* \brief [Interpolation
* search](https://en.wikipedia.org/wiki/Interpolation_search) algorithm
*/
#include <iostream>
/** function to search the value in an array using interpolation search /******************************************************************************
* \param [in] arr array to search in * @file
* \param [in] value value to search for * @brief [Interpolation search
* \param [in] len length of array * algorithm](https://en.wikipedia.org/wiki/interpolation_search)
* \returns index where the value is found *
* \returns 0 if not found * @details
*/ * interpolation search resembles the method by which people search a telephone
int interpolation_search(int arr[], int value, int len) { * directory for a name (the key value by which the book's entries are ordered):
int low = 0, high, mid; * in each step the algorithm calculates where in the remaining search space
high = len - 1; * 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) { * ### Complexities
mid = (low + *
((value - arr[low]) * (high - low)) / (arr[high] - arr[low])); * //n is the number of element in the array.
if (arr[mid] > value) *
high = mid - 1; * Worst-case time complexity O(n) (when items are distributed
else if (arr[mid] < value) exponentially)
low = mid + 1; * Average time complexity O(log2(log2 n))
else * space complexity 0(1)
return mid; *
* @author [Lajat Manekar](https://github.com/Lazeeez)
* @author Unknown author
*******************************************************************************/
#include <algorithm> /// for std::sort function
#include <cassert> /// for std::assert
#include <iostream> /// for IO operations
#include <vector> /// 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<uint64_t> &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<uint64_t>(high - low) / (arr[high] - arr[low])) *
(number - arr[low]));
if (arr[pos] == number) {
return pos; // Condition of target found
} }
if (arr[low] == value) if (arr[pos] < number) {
return low; 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
}
}
return -1; 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<uint64_t> 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 main() {
int n, value, re; tests(); // run self-test implementations
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;
return 0; return 0;
} }