我有一个程序,我已经做了很长一段时间了。我需要制作一个程序,通过回溯解决用户指定的求和难题。用户分别输入三个strings
,前两个strings
加起来应该等于第三个string
。
例子:
java + next = scala
4656 + 7980 = 12636
我相信我走在正确的轨道上,但我需要获取每个值的索引,<Character>
ArrayList
并让它们总和小于20,000
. 我该怎么做呢?
下面是我到目前为止的代码:
import java.util.*;
public class SummationPuzzle
{
public static ArrayList<Character> fsList = new ArrayList<Character>();
public static ArrayList<Character> lastW = new ArrayList<Character>();
public static ArrayList<Character> finaList = new ArrayList<Character>();
/**
* Reads in 3 words entered by user and converts the first two string into a single <Character> ArrayList
* takes the third string entered and converts it into it's own <Character>ArrayList
* @param firstW
* @param secondW
* @param thirdW
*/
public static void convertStr(String firstW, String secondW, String thirdW)
{
String combined = firstW + secondW;
for(int i = 0; i< combined.length(); i++)
{
fsList.add(combined.charAt(i));
}
for(int j = 0; j< thirdW.length(); j++)
{
lastW.add(thirdW.charAt(j));
}
System.out.println( fsList +" "+lastW);
swapAdd(fsList, lastW);
//feeds the resulting lists into the swapAdd method
}
/**@param
* This method Swaps the first char of fsList with the char at fsList[1]to make sure it matches the char at lastW[1]
* @param fsList
* @param lastW
*/
public static void swapAdd(ArrayList<Character> fsList, ArrayList<Character> lastW)
{
Collections.swap(lastW, 0,1);
System.out.println(lastW + " lastW swap first char");
char temp = lastW.get(1);
int j= 0;
System.out.println(fsList+ " before swap");
if(!fsList.get(1).equals(temp) && fsList.contains(temp))
{
j = fsList.indexOf(temp);
Collections.swap(fsList,1,j);
}
System.out.println(fsList+ " after swap");
removeDuplicate(fsList, lastW);
}
/**
* Combines two <Character> ArrayList into a one <Character> ArrayList with single instances of the char
* @param fsList
* @param lastW
*/
public static void removeDuplicate(ArrayList<Character> fsList, ArrayList<Character> lastW)
{
ArrayList<Character> tempList = new ArrayList<Character>();
tempList.addAll(fsList);
tempList.addAll(lastW);
for(char dupLetter : tempList)
{
if(!finaList.contains(dupLetter))
{
finaList.add(dupLetter);
}
}
System.out.println(finaList + "This is the list with duplicates removed");
System.out.println(lastW);
}
//main method
public static void main(String[] args)
{
//Receive user input
Scanner userIn = new Scanner(System.in);
System.out.println("Please enter your first word");
String firstW = userIn.next().trim();
System.out.println("Please enter your Second word");
String secondW = userIn.next().trim();
System.out.println("Please enter your Third word");
String thirdW = userIn.next().trim();
//print the summation puzzle
System.out.println(firstW+ " + " + secondW + " = "+ thirdW);
convertStr(firstW, secondW, thirdW);
}
}