hdu 4964 Emmet()模拟

题目大意：给定语句，依照语法翻译并输出。

解题思路：用递归模拟文法分析，主要注意几点：

括号而且的情况：(fuck)(you)
括号嵌套的情况：((fuck.you))
优先输出id，然后是class（题目中有说）
乘法的部分：fuck*2>you*3 （每次运行fuck时。you的地方相同被运行了3次）

其它跑出例子基本没问题，详细看代码。

#include <cstdio>
#include <cstring>
#include <string>
#include <vector>
#include <iostream>
#include <algorithm>

using namespace std;
typedef vector<string> VS;
const int manx = 1005;

int mv, N;
string str, word;

bool isletter (char ch) {
    if (ch >= 'a' && ch <= 'z')
        return true;
    if (ch >= 'A' && ch <= 'Z')
        return true;
    if (ch >= '0' && ch <= '9')
        return true;
    if (ch == '_')
        return true;
    return false;
}

int changeTonumber () {
    int ret = 0;
    for (int i = 0; i < word.size(); i++)
        ret = ret * 10 + word[i] - '0';
    return ret;
}
string getword () {
    string cur = "";
    while (isletter(str[mv]))
        cur = cur + str[mv++];
    mv--;
    return cur;
}

void gettoken () {

    if (mv == str.size()) {
        word = "";
        return;
    }

    while (str[mv] == ' ')
        mv++;

    switch (str[mv]) {
        case '.':
            word = ".";
            break;
        case '#':
            word = "#";
            break;
        case '>':
            word = ">";
            break;
        case '(':
            word = "(";
            break;
        case ')':
            word = ")";
            break;
        case '*':
            word = "*";
            break;
        default:
            word = getword();
            break;
    }
    mv++;
}

void putstring (string name, VS setid, VS setclass) {
    cout << "<" << name;

    if (setid.size() != 0) {
        cout << " id="" << setid[0];
        for (int i = 1; i < setid.size(); i++)
            cout << " " << setid[i];
        cout << """;
    }

    if (setclass.size() != 0) {
        cout << " class="" << setclass[0];
        for (int i = 1; i < setclass.size(); i++)
            cout << " " << setclass[i];
        cout << """;
    }

    cout << ">";
}

void solve () {
    int ret = mv, x, y, ti = 1;
    string recstring = "";

    gettoken();
    while (word == "(") {
        solve();
        // now word is ")";
        gettoken(); // get a new token;
    }

    if (word == ">") { // after solve '()';
        solve();
        return;
    }

    if (word == "" || word == ")")
        return;

    string name;
    VS setclass, setid;

    while (true) {

        if (word == ".") {
            gettoken();
            setclass.push_back(word);
        } else if (word == "#") {
            gettoken();
            setid.push_back(word);
        } else if (word == ">") {
            putstring(name, setid, setclass);
            solve();
            break;
        } else if (word == ")" || word == "") {
            putstring(name, setid, setclass);
            break;
        } else if (word == "*") {
            x = mv - 1;
            gettoken();
            y = mv;
            ti = changeTonumber();
            for (int i = x; i < y; i++) {
                recstring += str[i];
                str[i] = ' ';
            }
        } else
            name = word;
        gettoken();
    }
    cout << "</" << name << ">";

    for (int i = 1; i < ti; i++) {
        mv = ret;
        solve();
    }

    for (int i = 0; i < recstring.size(); i++)
        str[i+x] = recstring[i];
}

int main () {
    int cas;
    cin >> cas;
    while (cas--) {
        cin >> str;
        mv = 0;
        solve();
        cout << endl;
    }
    return 0;
}