Update selection sort example

cpp/algorithms/sorting/selection/CMakeLists.txt

@@ -1,6 +1,6 @@
 ###############################################################################
 ## Author: Shaun Reed                                                        ##
-## Legal: All Content (c) 2020 Shaun Reed, all rights reserved               ##
+## Legal: All Content (c) 2021 Shaun Reed, all rights reserved               ##
 ## About: A basic CMakeLists configuration to practice selection sort        ##
 ##                                                                           ##
 ## Contact: shaunrd0@gmail.com  | URL: www.shaunreed.com | GitHub: shaunrd0  ##

cpp/algorithms/sorting/selection/lib-select.cpp

@@ -1,6 +1,6 @@
 /*#############################################################################
 ## Author: Shaun Reed                                                        ##
-## Legal: All Content (c) 2020 Shaun Reed, all rights reserved               ##
+## Legal: All Content (c) 2021 Shaun Reed, all rights reserved               ##
 ## About: An example implementation of selection sort using a custom library ##
 ##                                                                           ##
 ## Contact: shaunrd0@gmail.com  | URL: www.shaunreed.com | GitHub: shaunrd0  ##
@@ -9,41 +9,18 @@
 
 #include "lib-select.h"
 
-#include <iostream>
+#include <vector>
 
-static int FindMinIndex(int const arr[], int start) {
+void SelectionSort(std::vector<int> &arr) {
-  // Assume we are at the minimum index until another is found
+  for (int leftIndex = 0; leftIndex < arr.size(); leftIndex++) {
-  int min = start;
+    // Get the index for the minimum number in the unsorted set
-  for (int i = start; i < 10; i++) {
+    int min = leftIndex;
-    if (arr[min] > arr[i]) min = i;
+    for (int i = leftIndex; i < arr.size(); i++) {
+      // Check if value at i is smaller than value at min index
+      min = (arr[min] > arr[i]) ? i : min; // Update min value to i if true
     }
-  return min;
-}
-
-int * RandomArray() {
-  static int newArray[ARRAY_LENGTH];
-  srand(time(NULL));
-
-  int randMax = 1000;
-  for (int i = 0; i < ARRAY_LENGTH; i++) {
-    newArray[i] = random() % randMax;
-  }
-  return newArray;
-}
-
-void SelectionSort(int arr[]) {
-  for (int leftIndex = 0; leftIndex < ARRAY_LENGTH; leftIndex++) {
-    // Check for a different minimum in the unsorted portion of the array
-    int min = FindMinIndex(arr, leftIndex);
 
     // If the minimum index has changed from it's origin, swap the elements
     if (min != leftIndex) std::swap(arr[leftIndex], arr[min]);
   }
 }
-
-void PrintArray(int arr[]) {
-  for (int i = 0; i < ARRAY_LENGTH; i++) {
-    std::cout << arr[i] << std::endl;
-  }
-  std::cout << std::endl;
-}

cpp/algorithms/sorting/selection/lib-select.h

@@ -1,6 +1,6 @@
 /*#############################################################################
 ## Author: Shaun Reed                                                        ##
-## Legal: All Content (c) 2020 Shaun Reed, all rights reserved               ##
+## Legal: All Content (c) 2021 Shaun Reed, all rights reserved               ##
 ## About: An example implementation of selection sort using a custom library ##
 ##                                                                           ##
 ## Contact: shaunrd0@gmail.com  | URL: www.shaunreed.com | GitHub: shaunrd0  ##
@@ -12,23 +12,12 @@
 
 #define ARRAY_LENGTH 10
 
-/** RandomArray
+#include <vector>
- * Returns an array automatically filled with random values
- *  Sizes array to match length setting ARRAY_LENGTH
- * @return A pointer to a static array
- */
-int * RandomArray();
 
 /** SelectionSort
  * Sorts an array of integers in ascending order
  * @param arr The array to sort
  */
-void SelectionSort(int arr[]);
+void SelectionSort(std::vector<int> &arr);
-
-/** PrintArray
- * Prints an array based on the define ARRAY_LENGTH
- * @param arr The array to print
- */
-void PrintArray(int arr[]);
 
 #endif // LIB_SELECT_H

cpp/algorithms/sorting/selection/select-sort.cpp

@@ -1,6 +1,6 @@
 /*#############################################################################
 ## Author: Shaun Reed                                                        ##
-## Legal: All Content (c) 2020 Shaun Reed, all rights reserved               ##
+## Legal: All Content (c) 2021 Shaun Reed, all rights reserved               ##
 ## About: An example implementation of selection sort using a custom library ##
 ##                                                                           ##
 ## Contact: shaunrd0@gmail.com  | URL: www.shaunreed.com | GitHub: shaunrd0  ##
@@ -9,19 +9,32 @@
 
 #include "lib-select.h"
 
+#include <algorithm>
 #include <iostream>
+#include <vector>
 
 int main(const int argc, char const * argv[]) {
-  // Create a random array based on ARRAY_LENGTH setting in lib-select.cpp
+  // Create a random vector with size ARRAY_LENGTH set within lib-select.cpp
-  int * numArray = RandomArray();
+  std::srand(time(nullptr));
+  std::vector<int> array(ARRAY_LENGTH, 0);
+  std::generate(array.begin(), array.end(), [](){return rand() % 1000;});
 
+  // Lambda for printing a vector
+  auto print = [](std::vector<int> const &array)->void {
+    for (const auto &i : array) std::cout << i << ", ";
+    std::cout << std::endl;
+  };
+
+  // Print vector before we sort it
   std::cout << "Unsorted array: \n";
-  PrintArray(numArray);
+  print(array);
 
-  // Sort the array and print the new contents
+  // Sort the vector
-  SelectionSort(numArray);
+  SelectionSort(array);
+
+  // Print sorted vector
   std::cout << "\nSorted array: \n";
-  PrintArray(numArray);
+  print(array);
 
   return 0;
 }