java

链接

java都需要在src中运行，用一目录下java类是默认都引用的，若在不同文件夹下需要package

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String s = scanner.nextLine();
        String[] strs = s.split(";");
        String[] scores = strs[1].split(",");
        System.out.printf("The each subject score of No. %d is %.2f, %.2f, %.2f.", Integer.parseInt(strs[0]), Float.parseFloat(scores[0]), Float.parseFloat(scores[1]), Double.parseDouble(scores[2]));
    }
}

//排序数组
import java.util.Arrays;
import java.util.Comparator;
import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        Integer [] a = new Integer[n]; //不能用基本数据类型
        for(int i=0; i<n; i++) a[i] = sc.nextInt();
        Arrays.sort(a, 1,n,new Comparator<Integer>() {
            @Override
            public int compare(Integer o1, Integer o2) {
                return o2 - o1;
            }
        });
        System.out.println(Arrays.toString(a));
    }
}
//排序类
import java.util.Arrays;
import java.util.Comparator;
import java.util.Scanner;

class Data implements Comparable<Data> {
    private int x;
    private double y;
    private String z;
    public Data(int x,double y,String z) {
        this.x = x;
        this.y = y;
        this.z = z;
    }
    public int getX() {
        return x;
    }
    public double getY() {
        return y;
    }
    public String getZ() {
        return z;
    }

    public int compareTo(Data t) {
        return x - t.x;
    }
}
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        Data [] datas = new Data [n];
        for(int i=0; i<n; i++) {
            datas[i]= new Data(sc.nextInt(),sc.nextDouble(),sc.next());
        }
        Arrays.sort(datas);
        for(Data data : datas) System.out.printf("%d %.2f %s\n",data.getX(),data.getY(),data.getZ());
    }
}


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

class Data {
    private int x;
    private double y;
    private String z;
    public Data(int x,double y,String z) {
        this.x = x;
        this.y = y;
        this.z = z;
    }
    public int getX() {
        return x;
    }
    public double getY() {
        return y;
    }
    public String getZ() {
        return z;
    }
}
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        Data [] datas = new Data [n];
        for(int i=0; i<n; i++) {
            datas[i]= new Data(sc.nextInt(),sc.nextDouble(),sc.next());
        }
        Arrays.sort(datas,0,n,new Comparator<Data>() {
            public int compare(Data o1,Data o2) {
                return o1.getX() - o2.getX();
            }
        });
        for(Data data : datas) System.out.printf("%d %.2f %s\n",data.getX(),data.getY(),data.getZ());
    }
}

Map

HashMap<Integer,Integer> mp = new HashMap<>();
mp.put(1,10);
mp.put(1,mp.get(1) + 1);
for(Map.Entry<Integer,Integer> entry : mp.entrySet()) {
    System.out.printf("%d %d\n",entry.getKey(),entry.getValue());
}

class Solution {
    public int getNumberOfK(int[] nums, int k) {
        HashMap<Integer,Integer> mp = new HashMap<>();
        for(int num : nums) {
            if(mp.containsKey(num) == true) mp.put(num,mp.get(num) + 1);
            else mp.put(num,1);
        }
        return mp.containsKey(k) ? mp.get(k) : 0;
      //retur mp.get(k) == null ? 0 : mp.get(k);
    }
}