数列排序

问题描述
给定一个长度为n的数列，将这个数列按从小到大的顺序排列。1<=n<=20000

输入格式
第一行为一个 整数n
第二行包括n个整数，为待排序的数，每个整数的绝对值小于20000
输出格式
输出一行，按从小到大的顺序输出排序后的数列

样例输入
5
8 3 6 4 9 
样例输出
3 4 6 8 9 

方法一：

冒泡排序法

import java.util.Scanner;

public class SequenceOfSorting {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n = scanner.nextInt();
        int []arr = new int[n];
        //往数组里添加元素
        for (int i = 0; i < n; i++) {
            arr[i] = scanner.nextInt();
        }
        int temp = 0;
        //排序
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < n - i - 1; j++) {
                if (arr[j] > arr[j + 1]){
                    temp = arr[j];
                    arr[j] = arr[j + 1];
                    arr[j + 1] = temp;
                }
            }
        }
        //打印数组
        for (int i = 0; i < n; i++) {
            System.out.print(arr[i] + " ");
        }
    }
}

运行结果

方法二：

直接插入排序

import java.util.Scanner;

public class SequenceOfSorting2 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n = scanner.nextInt();
        int []arr = new int[n];

        for (int i = 0; i < n; i++) {
            arr[i] = scanner.nextInt();
        }

        for (int i = 0; i < n; i++) {
            for (int j = i;j > 0;j--){
                if (arr[j - 1] > arr[j]){
                    int temp = arr[j - 1];
                    arr[j - 1] = arr[j];
                    arr[j] = temp;
                }
            }
        }

        for (int i = 0; i < n; i++) {
            System.out.print(arr[i] + " ");
        }
    }
}

运行结果

方法三：

选择排序

import java.util.Scanner;

public class SequenceOfSorting3 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n = scanner.nextInt();
        int []arr = new int[n];

        for (int i = 0; i < n; i++) {
            arr[i] = scanner.nextInt();
        }

        for (int i = 0; i < n; i++) {
            int temp = i;
            for (int j = i;j < n;j++){
                if (arr[j] < arr[temp]){ // 将数组里最小元素的下标赋值给temp
                    temp = j;
                }
            }
            int temp1 = arr[i];
            arr[i] = arr[temp];
            arr[temp] = temp1;
        }

        for (int i = 0; i < n; i++) {
            System.out.print(arr[i] + " ");
        }
    }
}

运行结果

方法四：

使用工具类java.util.Arrays

import java.util.Arrays;
import java.util.Scanner;

public class SequenceOfSorting {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        int n = scanner.nextInt();
        int []arr = new int[n];
        //往数组里添加元素
        for (int i = 0; i < n; i++) {
            arr[i] = scanner.nextInt();
            }
        Arrays.sort(arr);//排序

        //遍历输出数组数据
        for (int i = 0; i < n; i++) {
            System.out.print(arr[i] + " ");
        }
        }
    }