练习8.13

include <iostream>
#include <sstream>
#include <fstream>
#include <string>
#include <vector>
using namespace std;struct PersonInfo 
{string name;vector<string> phones;
};bool valid(const string& str)
{return isdigit(str[0]);
}string format(const string& str)
{return str.substr(0,3) + "-" + str.substr(3,3) + "-" + str.substr(6);
}int main()
{ifstream ifs("phonenumbers.txt");if (!ifs){cerr << "no phone numbers?" << endl;return -1;}string line, word;vector<PersonInfo> people;istringstream record;while (getline(ifs, line)){PersonInfo info;record.clear();record.str(line);record >> info.name;while (record >> word)info.phones.push_back(word);people.push_back(info);}for (const auto &entry : people){ostringstream formatted, badNums;for (const auto &nums : entry.phones)if (!valid(nums)) badNums << " " << nums;else formatted << " " << format(nums);if (badNums.str().empty())cout << entry.name << " " << formatted.str() << endl;elsecerr << "input error: " << entry.name<< " invalid number(s) " << badNums.str() << endl;}return 0;
}