与创建三鼎OJ的大牛同学相比，我只是个普通的不能在普通，算法上资质平平的人了，我写下的题解没什么精妙的解法，只是截止至写题解的时候我这个普通人对这道题的思维吧，这是我的第一篇题解，希望能帮助到大家，也恳请大家的指导，今后请多指教，谢谢了。

import java.util.Scanner;

public class P1002 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String[][] strArr = new String[][]
                {
                        {"   "," _ ",},
                        {"  |"," _|","|_|","|_ ","| |"},
                        {"  |","|_ "," _|","|_|"}
                };//在这个二维数组中存入所有可能出现的字符串
        while (sc.hasNextInt())
        {
            int a = sc.nextInt();
            int b = sc.nextInt();
            int c = sc.nextInt();
            int d = sc.nextInt();
            int[] arr = new int[]{a,b,c,d};//将输入存入数组，便于遍历

            String temp = "";
            //用for循环一行一行输出，i用来确定输出到第几行了，也确定应该调用字符串数组strArr的哪一行字符串（一共三行）
            for (int i = 0; i < 3; i++) {
                for(int num : arr)//遍历，筛选，然后把对应的字符串接到temp上（也可以直接不换行输出）
                {
                    if(i == 0)
                    {
                        if(num == 1 || num == 4)
                        {
                            temp += strArr[i][0];
                        }
                        else//只是我偷懒，最好还是用else-if吧(下同)
                        {
                            temp += strArr[i][1];
                        }
                    }
                    if(i == 1)
                    {
                        if(num == 1 || num == 7)
                        {
                            temp += strArr[i][0];
                        }
                        else if (num == 2 || num == 3)
                        {
                            temp += strArr[i][1];
                        }
                        else if (num == 0)
                        {
                            temp += strArr[i][4];
                        }
                        else if (num == 5 || num == 6)
                        {
                            temp += strArr[i][3];
                        }else
                        {
                            temp += strArr[i][2];
                        }
                    }
                    if(i == 2)
                    {
                        if(num == 1 || num == 7 || num == 4)
                        {
                            temp += strArr[i][0];
                        }
                        else if (num == 2)
                        {
                            temp += strArr[i][1];
                        }
                        else if (num == 0 || num == 6 || num == 8)
                        {
                            temp += strArr[i][3];
                        }
                        else if (num == 5 || num == 3 || num == 9)
                        {
                            temp += strArr[i][2];
                        }
                    }
                }
                System.out.println(temp);//输出temp
                temp = "";//重置temp，准备下一行录入
            }
        }
    }
}

《java辅导》：学打表，练习打表，....

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        String[][] str =
                {{" _ ","| |","|_|"},
                {"   ","  |","  |"},
                {" _ "," _|","|_ "},
                {" _ "," _|"," _|"},
                {"   ","|_|","  |"},
                {" _ ","|_ "," _|"},
                {" _ ","|_ ","|_|"},
                {" _ ","  |","  |"},
                {" _ ","|_|","|_|"},
                {" _ ","|_|"," _|"}};
        Scanner sc = new Scanner(System.in);
        while(sc.hasNext()){
            String s = sc.nextLine();
            char[] chs = s.toCharArray();
            for (int i = 0; i < 3; i++) {
                for (char ch: chs){
                    if(ch >= '0' && ch<= '9') {
                        System.out.print(str[ch - '0'][i]);
                    }
                }
                System.out.println();
            }
            System.out.println();
        }
    }
}

switch分行输出，暴力解

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int[] arr = new int[4];
        while(sc.hasNextInt()){
            arr[0] = sc.nextInt();
            arr[1] = sc.nextInt();
            arr[2] = sc.nextInt();
            arr[3] = sc.nextInt();

            for(int i = 0;i < 4;i++){
                if(arr[i] == 1 || arr[i] == 4){
                    System.out.print("   ");
                }else{
                    System.out.print(" _ ");
                }
            }
            System.out.println();

            for(int i = 0;i < 4;i++){
                switch (arr[i]){
                    case 1:
                    case 7:
                        System.out.print("  |");
                        break;
                    case 2:
                    case 3:
                        System.out.print(" _|");
                        break;
                    case 4:
                    case 8:
                    case 9:
                        System.out.print("|_|");
                        break;
                    case 5:
                    case 6:
                        System.out.print("|_ ");
                        break;
                    case 0:
                        System.out.print("| |");
                        break;

                }
            }
            System.out.println();

            for(int i = 0;i < 4;i++){
                switch (arr[i]){
                    case 1:
                    case 4:
                    case 7:
                        System.out.print("  |");
                        break;
                    case 2:
                        System.out.print("|_ ");
                        break;
                    case 3:
                    case 5:
                    case 9:
                        System.out.print(" _|");
                        break;
                    case 6:
                    case 8:
                    case 0:
                        System.out.print("|_|");
                        break;

                }
            }
            System.out.println();
        }

    }
}