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Selection Sort

Written by

Sonal Moga

Selection Sort

It is a sorting algorithm mainly performs an in-place comparison sort. Selection sort cannot be said to be very efficient on large lists.

Selection sort is a very simple algorithm and also has performance advantages over other sorting algorithms. Selection sort has a complexity of O(n²), where n is the number of items being sorted.

# Steps followed in the algorithm

  • Find the minimum value in the list
  • Swap it with the value at the first pos
  • Repeat the process till the last value is read and swapped.

# Algorithm

// selection sort

for (i = 0; i < array; i++;)


{


pos = min_pos_search(list, i);


temp = list[pos];


list[pos] = list[i];


list[i] = temp;


}

Code:

//Program to show selection sort

#include<iostream>
using namespace std;


int smallestNum(int[], int);


int main()


{


int array[5] = {
20,
5,
12,
35,
48
};


int position, temp, iter = 0;


cout << "\n Input list of elements to be Sorted\n";


for (int i = 0; i < 5; i++)


{


cout &lt;&lt; array[i] &lt;&lt; "\t";



}


for (int i = 0; i < 5; i++)


{


position = smallestNum(array, i);

temp = array[i];

array[i] = array[position];

array[position] = temp;

iter++;



}


cout << "\n Sorted list of elements is\n";


for (int i = 0; i < 5; i++)


{


cout &lt;&lt; array[i] &lt;&lt; "\t";



}


cout << "\nNumber of iterations required to sort the array: " << iter;


return 0;


}


int smallestNum(int array[], int i)


{


int small, pos, j;


small = array[i];


pos = i;


for (j = i + 1; j < 5; j++)


{


if (array[j] &lt; small)

{

  small = array[j];

  pos = j;

}



}


return pos;


}

Selection Sort