题解 | #参数解析#

#include <array>
#include <cstddef>
#include <iostream>
#include <list>
using namespace std;

size_t findNoSpace(const string& str, size_t index) {
    size_t len = str.length();
    for (int i = index; i < len; i++) {
        if (str.at(i) != ' ') {
            return i;
        }
    }
    return string::npos;
}

size_t rfindNoSpace(const string& str, size_t index) {
    for (int i = index; i >= 0; i--) {
        if (str.at(i) != ' ') {
            return i;
        }
    }
    return string::npos;
}

int main() {
    array<char, 1024> strSource = {0};
    while (cin.getline(strSource.begin(), 1024)) {
        string str(strSource.begin());
        size_t lastNoSpace = findNoSpace(str, 0);
        if (lastNoSpace == string::npos) {
            cout << 1 << endl << str << endl;
            return 0;
        }
        size_t lastQuota = 0;
        bool flag = false;
        list<string> res;
        size_t len = str.length();
        for (int i = lastNoSpace; i < len; i++) {
            if (flag) {
                if (str.at(i) == '\"') {
                    flag = false;
                    size_t thisQuota = rfindNoSpace(str, i);
                    res.push_back(str.substr(lastQuota, thisQuota - lastQuota));
                    lastNoSpace = findNoSpace(str, i + 1);
                    i = lastNoSpace - 1;
                }
            } else {
                if (str.at(i) == '\"') {
                    flag = true;
                    lastQuota = findNoSpace(str, i + 1);
                } else if (str.at(i) == ' ') {
                    res.push_back(str.substr(lastNoSpace, i - lastNoSpace));
                    lastNoSpace = findNoSpace(str, i + 1);
                }
            }
        }
        size_t thisNoSpace = rfindNoSpace(str, len - 1);
        if (lastNoSpace <= thisNoSpace) {
            string temp = str.substr(lastNoSpace, thisNoSpace - lastNoSpace + 1);
            res.push_back(temp);
        }
        cout << res.size() << endl;
        for (const auto & s : res) {
            cout << s << endl;
        }
    }
    return 0;
}