선택정렬

package Sorting_Searching;

import java.util.Scanner;

public class problem0501 {
    public static void main(String[] args){
        Scanner in = new Scanner(System.in);
        int length = in.nextInt();
        int[] arr = new int[length];
        for (int i=0; i<length; i++){
            arr[i]= in.nextInt();
        }

        int min = 101;
        int index = 0;

        for (int i=0; i<length-1; i++){
            min = arr[i];
            index = i;
            for (int j=i+1; j<length; j++){
                if (arr[j]<min){
                    min = arr[j];
                    index = j;
                }
            }
            if (index!=i){
                int temp = arr[index];
                arr[index] = arr[i];
                arr[i] = temp;
            }
        }
        for (int i : arr){
            System.out.print(i+" ");
        }
        return ;
    }
}

• i뒤에 j가 배열 끝까지 순회하면서 최솟값 찾아서 arr[i]랑 바꿈
• 시간복잡도 : O(n^2)