Select sorting method

One 、 Introduction to selective sorting method

Selection sort （Selection sort） It is a simple and intuitive sorting algorithm , It is in a set of numbers to sort , Choose the smallest （ Or maximum ） Exchange a number of with the number of the first position ; Find the smallest number among the remaining numbers and exchange it with the number in the second position , That is, the sequence is placed at the end of the ordered sequence , So circular , Until all data elements are arranged .

Two 、 The basic principle

Select the smallest data element from the data elements to be sorted for the first time （ Or maximum ） An element of , Store at the beginning of the sequence , And then find the smallest of the remaining unsorted elements （ Big ） Elements , Then put it at the end of the sorted sequence .
And so on , Until the number of all data elements to be sorted is zero .
Selective sorting is an unstable sorting method .

demonstration
Original value ：55,23,87,62,16
First scan ： First find the minimum value in the sequence , Then exchange with the first element in the sequence
16,23,87,62,55
Second scan ： Start with the second item , Find the lowest value in this series except the first item , Then exchange positions with the second element
16,23,87,62,55
The third scan ： Start with the third item
16,23,55,62,87
Fourth scan ： Start with Item 4
16,23,55,62,87

3、 ... and 、 Implementation code （java）

import java.util.Arrays;

public class practice {
    
	public static void main(String []args) {
    
		int array[]= {
    1,2,35,8,9,};
		for (int i = 0; i < array.length-1; i++) {
    
			int minIndex=i;
			int min=array[i];
			for (int j = i+1; j < array.length; j++) {
    
				if (min>array[j]) 
				{
    
					min=array[j];
					minIndex=j;
				}
			}
			array[minIndex]=array[i];
			array[i]=min;
		}
		System.out.println(Arrays.toString(array));
	}
}