HNU 实验七 字符串 E-mail地址

• • 题目
  • 思路
  • AC代码

是一个字符串模拟题，就按照给定的点和@来进行模拟。

#include 
#include 
#include 
using namespace std;
bool have_alpha(string check){
    for(int i=0;check[i];++i){
        if(check[i]>='a'&&check[i]<='z')
            return true;
    }
    return false;
}
int main() {
	string s;
	cin >> s;
    //cout< point, at;
	for (int i = 0; s[i]; ++i) {
		if (s[i] == '@')
			at.emplace_back(i);
		if (s[i] == '.')
			point.emplace_back(i);
	}
	//合法的email中的.一定在@后面
	int move_point = 0, move_at = 0, len1 = at.size(), len2 = point.size(), point_index, at_index;
	while (move_point < len2 && move_at < len1) {
		point_index = point[move_point];
		at_index = at[move_at];
		//对应的两个在s中的下标
		if (at_index < point_index) {
			//.在@的后面
			string pre;
			if (move_point == 0) {
				//说明第一次出现.在@的后面
				pre = s.substr(0, at_index);
				//cout << "pre为" << pre << endl;
			} else {
				//说明在后面
				for (int i = point[move_point - 1] + 1; i < at_index; ++i) {
					pre += s[i];
				}
				//cout << "pre为" << pre << endl;
			}
			string last;
			for (int i = point_index + 1; s[i]; ++i) {
				if (s[i] >= 'a' and s[i] <= 'z')
					last += s[i];
				else
					break;//如果不是字母就跳出来
			}
			//cout << "last是" << last << endl;
			string middle = s.substr(at_index + 1, point_index - at_index - 1);
			//cout << "middle是" << middle << endl;
			if (have_alpha(pre) and middle.find('_') == -1 and  last != "")  {
						int cnt = 0;
						for (int k = 0; pre[k]; ++k) {
							if (pre[k] >= 'a' && pre[k] <= 'z')
								cnt++;
						}
						res += cnt * last.size();
						move_at++;
			} else {
				move_at++;
			}
		} else {
			move_point++;
		}
	}
	cout << res;
}