알고리즘( 정렬, 탐색 )

#1.선택정렬

import java.util.*;
class Main {
    public int[] solution(int n, int[] arr){
        for(int i=0; i<n-1; i++){
            int idx=i;
            for(int j=i+1; j<n; j++){
                if(arr[j]<arr[idx]) idx=j;
            }
            int tmp=arr[i];
            arr[i]=arr[idx];
            arr[idx]=tmp;
        }
        return arr;
    }
    public static void main(String[] args){
        Main T = new Main();
        Scanner kb = new Scanner(System.in);
        int n=kb.nextInt();
        int[] arr=new int[n];
        for(int i=0; i<n; i++) arr[i]=kb.nextInt();
        for(int x : T.solution(n, arr)) System.out.print(x+" ");
    }
}

 

 

#2.버블정렬

import java.util.*;
class Main {
    public int[] solution(int n, int[] arr){
        for(int i=0; i<n-1; i++){
            for(int j=0; j<n-i-1; j++){
                if(arr[j]>arr[j+1]){
                    int tmp=arr[j];
                    arr[j]=arr[j+1];
                    arr[j+1]=tmp;
                }
            }
        }
        return arr;
    }
    public static void main(String[] args){
        Main T = new Main();
        Scanner kb = new Scanner(System.in);
        int n=kb.nextInt();
        int[] arr=new int[n];
        for(int i=0; i<n; i++) arr[i]=kb.nextInt();
        for(int x : T.solution(n, arr)) System.out.print(x+" ");
    }

 

 

#3.삽입정렬

import java.util.*;
class Main {
    public int[] solution(int n, int[] arr){
        for(int i=1; i<n; i++){
            int tmp=arr[i], j;
            for(j=i-1; j>=0; j--){
                if(arr[j]>tmp) arr[j+1]=arr[j];
                else break;
            }
            arr[j+1]=tmp;
        }
        return arr;
    }
    public static void main(String[] args){
        Main T = new Main();
        Scanner kb = new Scanner(System.in);
        int n=kb.nextInt();
        int[] arr=new int[n];
        for(int i=0; i<n; i++) arr[i]=kb.nextInt();
        for(int x : T.solution(n, arr)) System.out.print(x+" ");
    }
}