按字典顺序排序字符串

时间:2014-01-19 11:04:53

标签: java algorithm sorting mergesort

根据词典顺序使用自定义词典(abcdefghijklmnopqrstuvwxyz的排列)对字符串数组进行排序。这是代码。

/*
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 * and open the template in the editor.
 */


import java.io.BufferedReader;

import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

/**
 *
 * @author sabertooth
 */
public class SortString {

    /**
     * @param args the command line arguments
     */
    private static char[] index;
    private static BufferedReader br;


    public static void main(String[] args) throws Exception {
        // TODO code application logic here
        br=new BufferedReader(new InputStreamReader(System.in));
        int testCases=Integer.parseInt(br.readLine());

        for(int i=0;i<testCases;i++)
        {
            String dictionary=br.readLine();

            index=new char[dictionary.length()];
            index=dictionary.toCharArray();

            int set=Integer.parseInt(br.readLine());

            String[] unsortedInput=new String[set];
            String[] sortedInput=new String[set];
            for(int j=0;j<set;j++)
            {
                unsortedInput[j]=br.readLine();
            }

            if(unsortedInput.length<=1)
            {
                System.out.println(unsortedInput[0]);
            }
            else
            {
                // merge sort on this array
                sortedInput=mergeSort(unsortedInput);
                for(int k=0;k<sortedInput.length;k++)
                {
                    System.out.println(sortedInput[k]);
                }
            }
        }
    }

    private static String[] mergeSort(String[] unsortedInput){


        if(unsortedInput.length<=1)
        {
            return unsortedInput;
        }

        String[] left;
        String[] right;
        int middle=unsortedInput.length/2;
        if(unsortedInput.length%2==0)
        {
            left=new String[middle];
            right=new String[middle];
        }
        else
        {
            left=new String[middle];
            right=new String[middle+1];
        }
        System.arraycopy(unsortedInput, 0, left, 0, middle);
        System.arraycopy(unsortedInput, middle, right, 0, unsortedInput.length - middle);

        left=mergeSort(left);
        right=mergeSort(right);
        return merge(left,right);
    }

    private static String[] merge(String[] left, String[] right){
        List<String> leftList=new ArrayList<String>();
        List<String> rightList=new ArrayList<String>();

        List<String> result=new ArrayList<String>();

        leftList.addAll(Arrays.asList(left));
        rightList.addAll(Arrays.asList(right));

        while(leftList.size()>0 || rightList.size()>0)
        {
            if(leftList.size()>0 && rightList.size()>0)
            {
                // my own comparison
                if(compare(leftList.get(0),rightList.get(0))==-1)
                {
                    // leftString is less than right string
                    result.add(leftList.get(0));
                    leftList=leftList.subList(1, leftList.size());
                }
                else if(compare(leftList.get(0),rightList.get(0))==1)
                {
                    //left string is greater than right string
                    result.add(rightList.get(0));
                    rightList=rightList.subList(1, rightList.size());
                }
                else if(compare(leftList.get(0),rightList.get(0))==0)
                {
                    // leftString is equal to right string
                    result.add(leftList.get(0));
                    leftList=leftList.subList(1, leftList.size());
                }
            }
            else if(leftList.size()>0)
            {
                for(int i=0;i<leftList.size();i++)
                {
                    result.add(leftList.get(i));
                }
                leftList.clear();
            }
            else if(rightList.size()>0)
            {
                for(int i=0;i<rightList.size();i++)
                {
                    result.add(rightList.get(i));
                }
                rightList.clear();
            }
        }
        String[] sortedInput=new String[result.size()];
        for(int i=0;i<result.size();i++)
        {
            sortedInput[i]=result.get(i);
        }
        return sortedInput;
    }


    private static int compare(String leftString, String rightString){

        // return -1 if left string is less than right string else left string is greater than right string return 1

        int min=Math.min(leftString.length(), rightString.length());
        int response=0;
        for(int i=0;i<min;i++)
        {
            if(compareChar(leftString.charAt(i), rightString.charAt(i))==-1)
            {
                response= -1;
                break;
            }
            else if(compareChar(leftString.charAt(i), rightString.charAt(i))==1)
            {
                response= 1;
                break;
            }
            else if(compareChar(leftString.charAt(i), rightString.charAt(i))==0)
            {
                response=0;

            }
        }
        return response;

    }

    private static int compareChar(char x,char y){
        // returns true if x <y
        int indexofx=0;
        int indexofy=0;
        int response=0;
        for(int i=0;i<index.length;i++)
        {
            if(index[i]==x)
            {
                indexofx=i;
            }
            if(index[i]==y)
            {
                indexofy=i;
            }
        }
        if(indexofx<indexofy)
        {
            response=-1;
        }
        else if(indexofx>indexofy)
        {
            response=1;
        }
        else if(indexofx==indexofy)
        {
            response=0;
        }

        return response;

    }

}

问题是当我为某些输入运行此输出时输出正确,而对于其他输出则输出不正确。我一直在调试它,但无法找到错误。

编辑:

Adriana was playing with the English alphabet. When she was done playing with the alphabet, she realised that she had jumbled up the positions of the letters. Now, given a set of words, she wondered what would be the dictionary ordering of these words based on the new alphabet ordering which she made.

In other words, given a permutation of the English alphabet, E and a set of words S, you need to output the lexicographical ordering of the words in the set S based on the new alphabet, E.

Input

The first line will contain a single integer, T, denoting the number of test cases. T lines follow.
For each test case: 
The first line will contain a string, E, the new alphabet ordering, which will be a permutation of 'abcdefghijklmnopqrstuvwxyz' 
The next line will contain a single integer M, the size of the set S. S lines follow, each containing a single word, containing lowercase latin characters.

Output

For each test case, output S lines, each line containing one word from the set S, ordered lexicographically.

Constraints

1 <= T <= 1000 
1 <= M <= 100 
1 <= |W| <= 50

Sample Input
2
abcdefghijklmnopqrstuvwxyz
2
aa
bb
bacdefghijklmnopqrstuvwxyz
2
aa
bb

Sample Output
aa
bb
bb
aa

1 个答案:

答案 0 :(得分:0)

这适用于任何给定的排列。为什么使用自定义排序函数(除非你必须对自定义类对象进行排序)当java为你提供内置函数时?

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.ArrayList;

class TestClass {
    public static ArrayList<String> res;
    static void sort(String dictionary, String[] words, int count){
        String eng = "abcdefghijklmnopqrstuvwxyz";
        String[] tempArray = new String[count];
        String temp="";
        char ch;
        int index, m=0;
        for(String x : words){
            temp = "";
            for(int l =0 ;l<x.length(); l++){
                ch = x.charAt(l);
                index = dictionary.indexOf(ch);
                temp = temp + eng.charAt(index);
            }
            tempArray[m] = temp;
            m++;
        }

        Arrays.sort(tempArray);
        for(String x : tempArray){
            temp = "";
            for(int l =0 ;l<x.length(); l++){
                ch = x.charAt(l);
                index = eng.indexOf(ch);
                temp = temp + dictionary.charAt(index);
            }
            res.add(temp);

        }
    }
    public static void main(String args[] ) throws Exception {
        res = new ArrayList<String>();
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String line = br.readLine();
        int N = Integer.parseInt(line);
        int count;
        String [] words;
        String dictionary;
        for (int i = 0; i < N; i++) {
            dictionary = br.readLine();
            count = Integer.parseInt(br.readLine());
            words = new String[count];
            for(int j =0; j<count; j++){
                words[j] = br.readLine();
            }
            sort(dictionary,words,count);
        }
        for(String x : res)
        System.out.println(x);
    }
}

我想这是某种算法挑战。是吗? :)