leetcode 929. Unique Email Addresses 独特的电子邮件地址

Problem: 929. Unique Email Addresses 独特的电子邮件地址

依次检查@是否存在，若存在分割字符串，后缀检查长度>4且最后存在.com，前缀去掉+和后续，去掉’.'，检查前缀长度>0

Code

class Solution { public: int numUniqueEmails(vector<string>& emails) { unordered_set<string> te; int a, n2; string pre, after, tmp; for(string& s : emails) { a = s.find('@'); if(a == string::npos) { continue; } pre = s.substr(0, a); after = s.substr(a + 1); n2 = after.size(); if(n2 <= 4) continue; if(after[n2-1]!='m' || after[n2-2]!='o'||after[n2-3]!='c'|| after[n2-4]!='.') { continue; } a = pre.find('+'); if(a!=string::npos) { pre = pre.substr(0, a); } tmp.clear(); for(char& c : pre) { if(c!='.') { tmp += c; } } if(tmp.size() == 0) continue; te.insert(tmp + "@" + after); } return (int)te.size(); } };