Nov 21, 2012

The Selection Sort in C++

Selection Sort
An elementary sorting technique which finds the smallest element in the array and then exchanges it with the element in the first position
 1 #include <iostream>
 2 
 3 class SelectionSort
 4 {
 5     public:
 6         SelectionSort();
 7         ~SelectionSort();
 8 
 9         void sort(int arr[], int size);
10 
11     private:
12         void exchange(int &x, int &y);
13 };
14 
15 //Constructor
16 SelectionSort::SelectionSort() {}
17 
18 //Destructor
19 SelectionSort::~SelectionSort() {}
20 
21 void SelectionSort::sort(int arr[], int size)
22 {
23     for(int outerLoopIdx = 0; outerLoopIdx < size - 1; ++outerLoopIdx)
24     {
25         int min = outerLoopIdx;
26         for(int innerLoopIdx = outerLoopIdx + 1; innerLoopIdx < size; ++innerLoopIdx)
27         {
28             if(arr[min] > arr[innerLoopIdx])
29             {
30                 min = innerLoopIdx;
31             }
32         }
33         exchange(arr[outerLoopIdx], arr[min]);
34     }
35 }
36 
37 void SelectionSort::exchange(int &x, int &y)
38 {
39     int t = x;
40     x = y;
41     y = t;
42 }
43 
44 void print(int arr[], int size)
45 {
46     for(int i = 0; i < size; ++i)
47         std::cout << arr[i] << " ";
48 }
49 
50 int main()
51 {
52     int arr[] = { 10, 65, 35, 25, 15, 75, 85, 45, 65 };
53     SelectionSort ss;
54     ss.sort(arr, 9);
55     print(arr, 9);
56 }

Output:

No comments :

Post a Comment