CCF201703-3 Markdown

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
/*
标题--1；无序列表--2；段落--3
标题
无序列表：
1.前面一次输入不是列表，那么先追加一个 “<ul>”，然后修改这次输入，前后加上 “<li>”和 “</li>”
2.前面一次输入是列表，直接修改这次输入内容，并删除上一个输入末行的 “</ul>”
3.在最后追加一个 “</ul>”
段落：
首先在输入末尾加上“</p>”
1.前面一次输入不是段落，那么这次输入的段落最前面加上 “<p>”
2.前面一次输入是一个段落，那么这次输入不操作；去掉上一次输入末尾的 “</p>”
强调；简单的替换
超链接：简单的替换

*/
vector<string> result = vector<string>();
enum Tuple{
    INIT,TITLE,LIST,PARA,NEWLINE
};
int TYPE = INIT;
int LAST_TYPE = INIT;
string str = "";
void do_title();
void do_list();
void do_para();
void do_emphysis(string&);
void do_link(string&);
int main()
{
    while(getline(cin,str)){
        if(str=="\0"){
            LAST_TYPE = TYPE;
            TYPE = NEWLINE;
            continue;
        }
        char ch = str[0];
        if(ch=='#'){ LAST_TYPE = TYPE; TYPE = TITLE; do_title(); }
        else if(ch=='*'){ LAST_TYPE = TYPE; TYPE = LIST; do_list();}
        else{ LAST_TYPE = TYPE; TYPE = PARA; do_para(); }
    }
    for(int i=0;i<result.size();i++)
        cout<<result[i]<<endl;
    return 0;
}
void do_link(string& str){
    string::size_type pos1,pos2,pos3,pos4;
    pos1 = str.find("[");
    pos2 = str.find("]");
    pos3 = str.find("(");
    pos4 = str.find(")");
    while(string::npos!=pos1){
        string str_a = str.substr(pos1+1,pos2-pos1-1);
        string str_b = str.substr(pos3+1,pos4-pos3-1);
        string insert_str = "<a href=\"";
        insert_str = insert_str + str_b;
        insert_str = insert_str + "\">";
        insert_str = insert_str + str_a;
        insert_str = insert_str + "</a>";
        str.replace(pos1,pos4-pos1+1,insert_str);
        pos1 = str.find("[");
        pos2 = str.find("]");
        pos3 = str.find("(");
        pos4 = str.find(")");
    }
}
void do_emphysis(string& str){
    string exc_str1 = "<em>";
    string exc_str2 = "</em>";
    string find_str = "_";
    int find_count = 0;
    string::size_type pos;
    pos = str.find(find_str);
    while(string::npos!=pos){
        find_count++;
        if(find_count%2==1){
            str.replace(pos,find_str.length(),exc_str1);
        }else{
            str.replace(pos,find_str.length(),exc_str2);
        }
        pos = str.find(find_str);
    }

}
void do_para(){
    string tmp = "";
    if(LAST_TYPE==PARA){
        string &last_para = result.back();
        last_para = last_para.substr(0,last_para.size()-4);
        tmp = str + "</p>";
    }else{
        tmp = str;
        tmp = string("<p>") + tmp;
        tmp = tmp + "</p>";
    }
    do_emphysis(tmp);
    do_link(tmp);
    result.push_back(tmp);
}
void do_list(){
    int i = 1;
    string tmp = "";
    for( ;i<str.size();i++){
        if(str[i]!=' ') break;
    }
    str = str.substr(i);
    if(LAST_TYPE==LIST){
        tmp = string("<li>") + str;
        tmp = tmp + "</li>";
        string pop_str = result.back();
        if(pop_str=="</ul>") result.pop_back();
    }else{
        result.push_back(string("<ul>"));
        tmp = string("<li>") + str;
        tmp = tmp + "</li>";
    }
    do_emphysis(tmp);
    do_link(tmp);
    result.push_back(tmp);
    result.push_back(string("</ul>"));
}
void do_title(){
    int star_count = 0;
    int i = 0;
    for( ;i<str.size()&&str[i]=='#';i++,star_count++);
    for( ;i<str.size()&&str[i]==' ';i++);
    string tmp = "<h";
    char ch = star_count + 48;
    tmp = tmp + ch + ">";
    tmp = tmp + str.substr(i);
    tmp = tmp + "</h" + ch + ">";
    do_emphysis(tmp);
    do_link(tmp);
    result.push_back(tmp);
}