字符串压缩算法

题目描述：用Java实现一个字符串压缩算法

Input ： "aaabbacc"
Output："3a2b1a2c"

/**
 * Created by Eakon on 2017/6/16.
 *
 * 字符串压缩
 *
 * Input:
 * aaabbacc
 *
 * Output:
 * 3a2b1a2c
 */
public class StringCompression {

    public static String stringCompression(String str){
        StringBuilder sb = new StringBuilder("");
        if(str!=null&&str.length()!=0){
            for(int i=0; i<str.length(); i++){
                char ch=str.charAt(i);
                int count=1;
                while(i+1<str.length()){
                    if((i+1)<str.length()&&(ch==str.charAt(i+1))){
                        i++;
                        count++;
                    }
                    else break;
                }
                sb.append(count).append(ch);
            }
        }
        return sb.toString();
    }

    public static void main(String[] args) {
        String str="aaabbacc";
        String result=stringCompression(str);
        System.out.println("压缩前："+str);
        System.out.println("压缩后："+result);
    }
}

字符串压缩前后