BOGO 排序
BOGO 排序 又叫猴子排序，该排序算法通过随机打乱序列，试图对序列进行排序；通过不断的打乱，理论上可以实现序列的排序；但该算法基于随机打乱再进行验证，因此时间消耗上可能很快（一次打乱），也可能很慢（无限次打乱）；
以下为源代码：
/**
* @file
* @brief Implementation of [Bogosort algorithm](https://en.wikipedia.org/wiki/Bogosort)
*
* @details
* In computer science, bogosort (also known as permutation sort, stupid sort, slowsort,
* shotgun sort, random sort, monkey sort, bobosort or shuffle sort) is a highly inefficient
* sorting algorithm based on the generate and test paradigm. Two versions of this algorithm
* exist: a deterministic version that enumerates all permutations until it hits a sorted one,
* and a randomized version that randomly permutes its input.Randomized version is implemented here.
*
* ### Algorithm
* Shuffle the array untill array is sorted.
*
* @author [Deep Raval](https://github.com/imdeep2905)
*/
#include
#include
#include
#include
/**
* @namespace sorting
* @brief Sorting algorithms
*/
namespace sorting {
/**
* Function to shuffle the elements of an array. (for reference)
* @tparam T typename of the array
* @tparam N length of array
* @param arr array to shuffle
* @returns new array with elements shuffled from a given array
*/
template
std::array shuffle (std::array arr) {
for (int i = 0; i < N; i++) {
// Swaps i'th index with random index (less than array size)
std::swap(arr[i], arr[std::rand() % N]);
}
return arr;
}
/**
* Implement randomized Bogosort algorithm and sort the elements of a given array.
* @tparam T typename of the array
* @tparam N length of array
* @param arr array to sort
* @returns new array with elements sorted from a given array
*/
template
std::array randomized_bogosort (std::array arr) {
// Untill array is not sorted
while (!std::is_sorted(arr.begin(), arr.end())) {
std::random_shuffle(arr.begin(), arr.end());// Shuffle the array
}
return arr;
}
} // namespace sorting
/**
* Function to display array on screen
* @tparam T typename of the array
* @tparam N length of array
* @param arr array to display
*/
template
void show_array (const std::array &arr) {
for (int x : arr) {
std::cout << x << ' ';
}
std::cout << '\n';
}
/**
* Function to test above algorithm
*/
void test() {
// Test 1
std::array arr1;
for (int &x : arr1) {
x = std::rand() % 100;
}
std::cout << "Original Array : ";
show_array(arr1);
arr1 = sorting::randomized_bogosort(arr1);
std::cout << "Sorted Array : ";
show_array(arr1);
assert(std::is_sorted(arr1.begin(), arr1.end()));
// Test 2
std::array arr2;
for (int &x : arr2) {
x = std::rand() % 100;
}
std::cout << "Original Array : ";
show_array(arr2);
arr2 = sorting::randomized_bogosort(arr2);
std::cout << "Sorted Array : ";
show_array(arr2);
assert(std::is_sorted(arr2.begin(), arr2.end()));
}
/** Driver Code */
int main() {
// Testing
test();
// Example Usage
std::array arr = {3, 7, 10, 4, 1}; // Defining array which we want to sort
std::cout << "Original Array : ";
show_array(arr);
arr = sorting::randomized_bogosort(arr); // Callling bogo sort on it
std::cout << "Sorted Array : ";
show_array(arr); // Printing sorted array
return 0;
}