Rework Bubble Sort C++

CONTRIBUTORS.md

@@ -40,3 +40,5 @@ GuyPozner
 <br>
 William Boyles
 <br>
+Benjamin Chislett
+<br>

chapters/algorithms/bubble_sort/code/c++/bubblesort.cpp

@@ -1,71 +1,39 @@
-#include <algorithm>
-#include <cstddef>
-#include <iostream>
-#include <iterator>
-#include <random>
+#include <stdlib.h> // rand
+#include <vector>   // vectors
+#include <iostream> // cout
+#include <algorithm>// swap
 
-using std::begin;
-using std::end;
-
-template <class Rng>
-std::vector<float> generate_input(std::size_t size, Rng& rng) {
-  auto dist = std::uniform_real_distribution<>(0.0, 1.0);
-
-  auto ret = std::vector<float>();
-  std::generate_n(std::back_inserter(ret), size,
-    [&rng, &dist] { return dist(rng); });
-
-  return ret;
-}
-
-template <class Iter>
-void print_range(std::ostream& os, Iter const first, Iter const last) {
-  os << '{';
-
-  if (first != last) {
-    os << *first;
-    std::for_each(first + 1, last, [&os] (double d) { os << ", " << d; });
-  }
-
-  os << "}\n";
-}
-
-template <class Iter>
-void bubble_sort(Iter const first, Iter const last) {
-  if (first == last) {
-    // the empty range is vacuously sorted
-    return;
-  }
-
-  for (;;) {
+std::vector<int> bubble_sort(std::vector<int> unsorted_list) {
+  while (true) {
     bool is_sorted = true;
-
-    for (auto it = first; it + 1 != last; ++it) {
-      // these are unsorted! gotta swap 'em
-      if (*(it + 1) < *it) {
-        using std::swap;
-        swap(*it, *(it + 1));
+    // Sweep through the array
+    for (unsigned int i = 0; i < unsorted_list.size() - 1; i++) {
+      // If next if smaller, swap, and keep sorting
+      if (unsorted_list[i + 1] < unsorted_list[i]) {
+        std::swap(unsorted_list[i], unsorted_list[i + 1]);
         is_sorted = false;
       }
     }
-
-    if (is_sorted) {
-      break;
-    }
+    // If we made it through without swapping anything, the list is sorted
+    if (is_sorted) { return unsorted_list; }
   }
 }
 
-int main() {
-  std::random_device random_device;
-  auto rng = std::mt19937(random_device());
-
-  auto input = generate_input(10, rng);
+int main()
+{
+  std::vector<int> to_be_sorted = {};
+  // Initialize and print a vector with 50 random integers of domain [0,1000]
+  for (int i = 0; i < 50; i++) {
+    int value = rand() % 1000;
+    std::cout << value << " ";
+    to_be_sorted.push_back(value);
+  }
+  std::cout << std::endl;
 
-  std::cout << "before sorting:\n";
-  print_range(std::cout, begin(input), end(input));
+  std::vector<int> sorted = bubble_sort(to_be_sorted);
 
-  bubble_sort(begin(input), end(input));
+  for (int i : sorted) { std::cout << i << " "; }
 
-  std::cout << "\nafter sorting:\n";
-  print_range(std::cout, begin(input), end(input));
+  return 0;
 }
+