java:数组，如何使用查找距离(距离，名称)函数和显示距离

Question

java ： 数组 ， 如何使用查找距离(距离，名称(函数和显示距离？
java：数组，如何使用查找距离(距离，名称(函数和显示距离？java：数组，如何使用查找距离(距离，名称(函数和显示距离？

package practice;
public class displayDistance 
{   
   /*I'm playing around with Arrays in Java and had this doubt.
     How do I call the  find Distance (distance,name) and display distance .
     5 Requirement are :
     1) Define 2-D Array for distance and populate it. 
     2) ask user for source and destination ( preferably lets use Exception Handling along with JOptionPane prompt .
        e.g. 1st prompt-> From city :  , 2nd prompt->  To city :    
     3)define a city Array 
     4)call function findDistance (distance,name) to find distance and  return it . 
     5)display distance.*/
    public class practice {
        public void main(String[] args) 
        {
          //1. Define 2-D Array for distance and populate it .      
          int [][] distances = { {0,50,100,20},{50,0,70,110},
                               {100,70,0,200},{20,110,200,0} };
          //3. define a city Array          
          String [] names = {"manassas","fairfax","baltimore","centerville"};       
          // calling (invoking)the function         
           findDistance (distances,names);

          // JOptionPane.showMessageDialog(null, "The distance value is: " + findDistance(distances), "DISTANCE VALUE",
          // JOptionPane.INFORMATION_MESSAGE);     
        }   
     private String findDistance(int[][] distances, String[] names) {                       
         return null;
     }
  }
}

Answer 1

import java.util.*;
import java.lang.*;
import java.io.*;
class Demo6 {
    public static void main(String[] args) {
        int[][] distances = {{0, 50, 100, 20}, {50, 0, 70, 110},
                {100, 70, 0, 200}, {20, 110, 200, 0}};
        String[] names = {"manassas", "fairfax", "baltimore", "centerville"};
        /* Take two more inputs which are FROM city TO city */
        /* I have taken two default city names below */
        /* And findDistance method should have four arguments */
        findDistance(distances, names, "baltimore", "centerville");
    }
    private static void findDistance(int[][] distances, String[] names, String a, String b) {
        int x = 0, y = 0;
        /*below i am finding the index of the cities 'a' and 'b'*/
        /*below logic works only if both the cities exist  in the array*/
        
        for (int i = 0; i < names.length; i++) {
            if (names[i].equals(a))
                x = i;
            if (names[i].equals(b))
                y = i;
        }
    /*after calculating the index just print their cost from the matrix distance*/
    /*its as simple as that*/
        System.out.println(distances[x][y]);
    }
}

希望对您有所帮助。我已经在注释中解释了代码。