我很难为我的程序创建排序方法。我创建了一个程序，如果想要从A-Z添加，删除，搜索或排序，则会询问用户。 继承我的程序代码
import java.util.Scanner;
import java.io.*;
/**
* Write a description of class Final_Project here.
*
* @author (your name)
* @version (a version number or a date)
*/
public class Final_Project
{
public static void main (String args[])throws IOException
{
Scanner c = new Scanner(System.in);
Scanner a = new Scanner(System.in);
Scanner f = new Scanner(System.in);
Scanner g = new Scanner(System.in);
String car[][] = new String [20][4];
System.out.println("JD Car Inventory");
System.out.println();
System.out.println();
while (true)
{
System.out.println();
System.out.println("What would you like to do?");
System.out.println("a= Add vehicle");
System.out.println("b= Delete vehicle");
System.out.println("c= Search Inventory");
System.out.println("d= Sort Inventory");
System.out.println("e= Exit Program");
System.out.println("f= View database");
System.out.println();
String get = g.nextLine();
System.out.println();
if (get.equalsIgnoreCase("a")){
a(car);
}
else if(get.equalsIgnoreCase("b")){
del(car);
}
else if (get.equalsIgnoreCase("c")){
search(car);
}
else if (get.equalsIgnoreCase("d")){
sort(car);
}
else if (get.equalsIgnoreCase("e"))
{
System.out.println ("Thank you for visiting JD CAR'S.");
break;
}
else if (get.equalsIgnoreCase("f"))
{
BufferedReader input = new BufferedReader (new FileReader("name.txt"));
for (int y=0;y<20;++y)
{
for (int x=0;x<4;++x)
{
String line = input.readLine();
car[y][x] = line;
if (line == null)
{
car[y][x] = "";
}
}
}
input.close();
PrintWriter output = new PrintWriter (new FileWriter("name.txt"));
for (int y=0; y<20; y++) //rows
{
for (int x=0; x<4; x++) //columns
{
System.out.print (String.format("%1$-" + 32 + "s", car[y][x]));
output.println(car[y][x]);
}
System.out.println ();
System.out.println("------------------------------------------------------------------------------------------------------------------------");
//output.println();
//output.println("-------------------------------------------------------------------------------------");
}
output.close();
}
else
{
System.out.println ("This is invalid. Enter again.");
}
}
}
public static void a (String car[][])throws IOException
{
Scanner sc = new Scanner(System.in);
for (int y=11;y<20;++y)
{
for (int x=0;x<4;++x)
{
if (car[y][x].equals(""))
{
while (true)
{
System.out.println ("What is the name of the vehicle?");
car[y][x] = sc.nextLine ();
x+=1;
System.out.println ("How much Horsepower does it have?");
car[y][x] = sc.nextLine ();
x+=1;
System.out.println ("What is the Engine Size (L)?");
car[y][x] = sc.nextLine ();
x+=1;
System.out.println ("What is the price ($)?");
car[y][x] = sc.nextLine ();
x+=1;
System.out.println ("Would you like to add more?");
String add = sc.nextLine ();
}
}
}
}
}
public static void del (String car[][])throws IOException
{
Scanner l = new Scanner(System.in);
Scanner cs = new Scanner(System.in);
System.out.println("Do you want to remove any vehicle?");
String del = l.nextLine();
if (del.equalsIgnoreCase("yes")){
System.out.println("Enter the field number you would like to remove (1,2,3,4)");
double d= cs.nextDouble();
System.out.println();
if (d == 1){
car[1][0] = "";
car[1][1] = "";
car[1][2] = "";
car[1][3] = "";
}
else if (d == 2){
car[2][0] = "";
car[2][1] = "";
car[2][2] = "";
car[2][3] = "";
}
else if (d == 3){
car[3][0] = "";
car[3][1] = "";
car[3][2] = "";
car[3][3] = "";
}
else if (d == 4){
car[4][0] = "";
car[4][1] = "";
car[4][2] = "";
car[4][3] = "";
}
else if (d == 5){
car[5][0] = "";
car[5][1] = "";
car[5][2] = "";
car[5][3] = "";
car[5][4] = "";
car[5][5] = "";
}
else if (d == 6){
car[6][0] = "";
car[6][1] = "";
car[6][2] = "";
car[6][3] = "";
}
else if (d == 7){
car[7][0] = "";
car[7][1] = "";
car[7][2] = "";
car[7][3] = "";
}
else if (d == 8){
car[8][0] = "";
car[8][1] = "";
car[8][2] = "";
car[8][3] = "";
}
else if (d == 9){
car[9][0] = "";
car[9][1] = "";
car[9][2] = "";
car[9][3] = "";
}
else if (d == 10){
car[10][0] = "";
car[10][1] = "";
car[10][2] = "";
car[10][3] = "";
}
}
}
public static void search( String car[][])throws IOException
{
Scanner f = new Scanner(System.in);
Scanner a = new Scanner(System.in);
Scanner o = new Scanner(System.in);
while(true){
System.out.println ("0 = Car Name");
System.out.println ("1 = Horsepower");
System.out.println ("2 = Engine Size");
System.out.println ("3 = Price");
int cNumber = f.nextInt ();
System.out.println ("Enter what to search?");
String sA = a.nextLine ();
boolean flag=true;
for (int j=11;j<20;++j)
{
for (int k=0;k<4;++k)
{
if(sA.equals (car[j][cNumber]))
{
while (true)
{
flag=true;
int t=0;
int q=0;
System.out.print (String.format("%1$-" + 32 + "s", car[t][q]));
q+=1;
System.out.print (String.format("%1$-" + 32 + "s", car[t][q]));
q+=1;
System.out.print (String.format("%1$-" + 32 + "s", car[t][q]));
q+=1;
System.out.print (String.format("%1$-" + 32 + "s", car[t][q]));
q+=1;
System.out.println();
break;
}
}
}
if (flag == false )
{
System.out.println();
System.out.println ("No search resulst for" + sA + ". Trying to see if you spelt the word right.");
}
System.out.println();
System.out.println ("Would you like to search again?");
sA = o.nextLine ();
if (sA.equalsIgnoreCase ("no"))
{
break;
}
}
}
}
public static void sort (String car[][])throws IOException
{
}
}
}
有人可以告诉我该怎么做，我应该使用冒泡排序吗？
答案 0 :(得分：1)
因为这看起来像研究，只有建议：
将问题拆分为已完成（最初为空）和做（最初为全部）。然后从待办事项中反复挑选一名候选人并增加其余部分。
有点像：
int sortedCars = 0;
while (sortedCars < car.length) {
// Pick the smallest from the unsorted cars:
int smallest = sortedCars;
for (int i = smallest + 1; i < car.length; i++) {
if (car[i] less than car[smallest]) {
smallest = i;
}
}
// Exchange car[sortedCars] with car[smallest]:
...
++sortedCars;
}
答案 1 :(得分：0)
我认为你不应该编写自己的排序方法。而是利用Java内置的Arrays.sort方法
EG。
Arrays.sort(car, new Comparator() {
public int compare(Object o1, Object o2) {
// compare based on which column you want
return o1[0].compareTo(o2[0]);
}
});