[算法]去掉字符串中连续出现的k个0子串

public static String removeKZeros(String str,int k){
        if (str == null||k<1) {
            return str;
        }
        char[] chas=str.toCharArray();
        int count=0,start=-1;
        for (int i=0;i!=chas.length;i++){
            if (chas[i]==‘0‘){
                count++;
                start=start==-1?i:start;
            }
            else {
                if (count==k){
                    while (count--!=0)
                        chas[start++]=‘@‘;
                }
                count=0;
                start=-1;
            }
        }
        if (count==k){
            while (count--!=0)
                chas[start++]=‘@‘;
        }
        return String.valueOf(chas).replaceAll("\\@+","");
    }