Research on the algorithm of------------bucket sorting based on algorithm introduction

To illustrate the process of sorting buckets, suppose there are now a={0.78,0.17,0.39,0.26,0.72,0.94,0.21,0.12,0.23,0.68}, the buckets are sorted as follows:

Study on the count sort we know ———— count sort is assumed that the input is made up of integers in a small range, whereas bucket ordering assumes that the input is produced by a random process that distributes the elements evenly and independently across the interval [0,1]. When the input of the bucket sort conforms to the uniform distribution, it can be expected to run linearly. The idea of barrel sequencing is: Divide the interval [0,1] into n equal-sized sub-ranges, become buckets (buckets), then distribute n input numbers into buckets, sort the number of buckets, and then list the elements in each bucket in order.

The pseudo-code for the bucket ordering is given, assuming that the input is an array of n elements, and each element satisfies 0≤a[i]<1, and an auxiliary array b[0....n-1] is required to hold the linked list (bucket). The pseudo-code looks like this:

Bucket_sort (A)
n = Length (A)
For i= 1 to N
Do insert a[i] into list B
For I=0 to N-1
Do sort list b[i] with insertion sort
Concatenate the list b[0], b[1],,,b[n-1] together in order

The Real bucket ordering is now based on pseudo-code, which uses the C + + method and the functions of the list and iterator in the STL . and sorting the elements in the bucket using the insertion sort algorithm.

<pre name= "code" class= "CPP" > #include <iostream> #include <vector> #include <list> #include <cstdlib>using namespace Std;void bucket_sort (float *datas, size_t length) {int I, j;int index;float fvalue;size_t l size;list<float> *retlist = new List<float>[length];list<float>::iterator iter;list<float>: : Iterator Prioiter, enditer;for (i = 0; i<length; ++i) {index = static_cast<int> (datas[i] *);//insert a new ele Mentretlist[index].push_back (Datas[i]); lsize = Retlist[index].size (); if (Lsize > 1) {//get The last element in the list [Index]iter =--retlist[index].end (); fvalue = *iter;enditer = Retlist[index].begin ();//insert the last element in right PO  Sitionwhile (iter! = enditer) {//get The second last element in the List[index]prioiter =--iter;//back up iter to the last element in the List[index]iter++;//compare-valuesif (* (prioiter)-*iter > 0.000001) {Float temp = * (Prioiter); * (prioiter) = *iter;*iter = temp;} iter--;}The right inserted position* (++iter) = Fvalue;}} Copy the result to DATASJ = 0;for (int i = 0; i<length; i++) {for (iter = Retlist[i].begin (); ITER! = Retlist[i].end () ; ++iter) datas[j++] = *iter;a}delete[] retlist;} int main () {float datas[10] = {0.78f, 0.17f, 0.39f, 0.76f, 0.23f, 0.67f, 0.48f, 0.58f, 0.92f, 0.12f};bucket_sort (datas, 1 0); cout << "After bucket_sort the result is:" << endl;for (int i = 0; i<10; i++) cout << datas[i] << ""; cout << endl;exit (0);}

Research on the algorithm of------------bucket sorting based on algorithm introduction