clean_phone.cpp

#include <iostream>
#include <string>

#include "phonenumbers/phonenumberutil.h"

using i18n::phonenumbers::PhoneNumber;
using i18n::phonenumbers::PhoneNumberUtil;

using namespace std;

const PhoneNumberUtil &util = *PhoneNumberUtil::GetInstance();

string format_number(string phone) {
    string formatted;
    PhoneNumber number;

    util.Parse(phone, "IN", &number);
    util.Format(number, PhoneNumberUtil::E164, &formatted);
    if (!util.IsValidNumber(number)) {
        return "";
    }
    return formatted;
}

int main() {
    for (string line; getline(cin, line);) {
        cout<<format_number(line)<<endl;
    }
    return 0;
}