package com.zsl.common.util;

import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.Map;


/**
 * 输入一串字符，请编写一个字符串压缩程序，将字符串中连续出现的重复字母进行压缩，并输出压缩后的字符串。
 * 例如：
 * aac 压缩为 1ac
 * xxxxyyyyyyzbbb 压缩为 3x5yz2b
 *
 * 针对问题采用的数据结构很重要
 * */
public class StringCompress {

    public static void main(String[] args) {
        String text="xxxxyyyyyybbbcccc";
        System.out.println("错误做法:"+compress1(text));
        System.out.println("正确做法:"+compress(text));
    }
    /**
     * 这个方法用LinkedHashMap装,导致重复数据会被覆盖
     * */
    public static String compress1(String str){
        if(str!=null&&str!=""){
            char[] chars=str.toCharArray();
            LinkedHashMap<Character,Integer> map=new LinkedHashMap<>();
            char nowChar;
            char nextChar;

            for (int i = 0; i <chars.length ; i++) {
                int count=0;
                nowChar=chars[i];
                System.out.println(i);
                if(i==chars.length-1){
                    map.put(nowChar,count);
                    break;
                }
                for (int j = i+1; j <chars.length ; j++) {
                    nextChar=chars[j];
                    if(nowChar==nextChar){
                        count+=1;
                        if(j==chars.length-1){
                            map.put(nowChar,count);
                            i=chars.length;
                        }
                    }else{
                        i=i+count;
                        map.put(nowChar,count);
                        break;
                    }

                }
            }
            System.out.println(map);
            StringBuffer stringBuffer=new StringBuffer();
            map.forEach((key,value)->{
                if(value!=0){
                    stringBuffer.append(value);
                    stringBuffer.append(key);
                }else{
                    stringBuffer.append(key);
                }
            });
            return stringBuffer.toString();
        }else{
            return str;
        }
    }
    /**
     * LinkedHashMap<Integer, Map<Character,Integer>>
     *     正确的做法
     * */
    public static String compress(String str){
        char[] chars=str.toCharArray();
        LinkedHashMap<Integer, Map<Character,Integer>> resultMap=new LinkedHashMap<>();
        char nowChar;
        char nextChar;
        int index=0;
        for (int i = 0; i <chars.length ; i++) {
            Map<Character,Integer> map=new HashMap<>();
            index+=1;
            int count=0;
            nowChar=chars[i];
            if(i==chars.length-1){
                map.put(nowChar,count);
                resultMap.put(index,map);
                break;
            }
            for (int j = i+1; j <chars.length ; j++) {
                nextChar=chars[j];
                if(nowChar==nextChar){
                    count+=1;
                    if(j==chars.length-1){
                        map.put(nowChar,count);
                        i=chars.length;
                    }
                }else{
                    i=i+count;
                    map.put(nowChar,count);
                    break;
                }
            }
            resultMap.put(index,map);
        }
        StringBuffer stringBuffer=new StringBuffer();

        resultMap.forEach((k,v)->{
            v.forEach((key,value)->{
                if(value!=0){
                    stringBuffer.append(value);
                    stringBuffer.append(key);
                }else{
                    stringBuffer.append(key);
                }
            });
        });
        return stringBuffer.toString();
    }

}