/*
1. 首先处理local name 为最终的情况，然后和domain一起加到set里即可
2. testCase:   null， 空
local正常， local 带. , local 带+, local 带.和+ ,  空
domain正常， domain 带. , domain 带+, domain 带.和+, 空

*/


class Solution {

    StringBuilder buffer = new StringBuilder();

    public int numUniqueEmails(String[] emails) {
        Set<String> set = new HashSet<>();

        for (int i = 0 ; i < emails.length ; i++){
            String realAddress = getRealAddress(emails[i]);
            set.add(realAddress);
        }

        return set.size();
    }

    public String getRealAddress(String email){
        buffer.setLength(0);
        boolean ignore = false;
        int i = 0;
        for (  ; i < email.length(); i++){

            if (email.charAt(i) == '.') continue;
            if (email.charAt(i) == '+') ignore = true;
            if (email.charAt(i) == '@') break;
            if (ignore) continue;
            buffer.append(email.charAt(i));
        }

        for ( ; i < email.length(); i++){
            buffer.append(email.charAt(i));
        }
        return buffer.toString();
    }


}