Add example for bucket sort

cpp/algorithms/sorting/bucket/lib-bucket.cpp

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+/*#############################################################################
+## Author: Shaun Reed                                                        ##
+## Legal: All Content (c) 2021 Shaun Reed, all rights reserved               ##
+## About: An example implementation of bucket sort using a custom library    ##
+##                                                                           ##
+## Contact: shaunrd0@gmail.com  | URL: www.shaunreed.com | GitHub: shaunrd0  ##
+###############################################################################
+*/
+
+#include "lib-bucket.hpp"
+
+#include <algorithm>
+#include <list>
+#include <vector>
+
+
+void BucketSort(std::vector<float> &array)
+{
+  // For this example, we need an array of linked lists
+  // + Each value of this array will be referred to as a bucket
+  // + Each list stores the values that fall within the range of that bucket
+  std::vector<std::list<float>> bucketArray(BUCKET_ARRAY_LENGTH);
+
+  // Truncation to zero will always floor the result of division
+  // + If the bucket contains negative values, convert them to their absolutes
+  // + Run BucketSort on the abs values, then convert them back to negative
+  // ++ For a mixed-bag of negative and positive, track which values you absolute
+  // ++ Then only negate those values after BucketSort
+  for (const auto & value : array) {
+    bucketArray[value / static_cast<float>(bucketArray.size())].push_back(value);
+  }
+
+  // Track the last used index in the final sorted array; Starting at 0
+  int currentIndex = 0;
+  // Sort each bucket in the bucketArray
+  for (std::list<float> &bucket : bucketArray) {
+    bucket.sort();
+    // After sorting each bucket, rewrite values in-order to final sorted array
+    for (const auto &value : bucket) array[currentIndex++] = value;
+  }
+
+}