【CCF 201703-3】Markdown

版权声明： https://blog.csdn.net/leelitian3/article/details/82193968

写在前面

CCF第三题，一道相对简单的字符串模拟题

思路

每次先读取一行line，先把“强调”和“超链接”处理完毕，然后分3种情况处理：

1.若line[0]为‘#’，说明是标题

2.若line[0]为“*”，说明是列表，反复读取并处理直到空行

3.说明是普通的段落，反复读取并处理直到空行

测试数据

C++代码

#include <iostream>
#include <iomanip>
#include <cstring>
#include <sstream>
using namespace std;

void deal_emphasis(string& a)
{
	int cnt = 0;
	size_t p;
	while((p = a.find("_")) != string::npos)
	{
		++cnt;
		if(cnt&1) a.replace(p,1,"<em>");
		else a.replace(p,1,"</em>");
	}
}

bool deal_url(string& a)
{
	int s1,s2,c1,c2;
	s1=s2=c1=c2=-1;
	for(size_t i=0; i<a.size(); ++i)
	{
		if(a[i]=='[') s1 = i;
		else if(a[i]==']') s2 = i;
		else if(a[i]=='(') c1 = i;
		else if(a[i]==')') c2 = i;
	}
	if(s1!=-1 && s2!=-1 && c1!=-1 && c2!=-1 && c1==s2+1)
	{
		string test(a.begin()+s1+1,a.begin()+s2);
		string link(a.begin()+c1+1,a.begin()+c2);
		string res = "<a href=\"" + link + "\">" + test + "</a>";
		a.replace(s1,c2-s1+1,res);
		return 1;
	}
	return 0;
}

void erase_blank(string& a)
{
	for(size_t i=0; i<a.length();)
	{
		if(a[i] == ' ') a.erase(i,1);
		else break;
	}
}

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);

	string tmp, t1,t2;
	stringstream ss;
	size_t i;

	while(getline(cin, tmp))
	{
		if(tmp.empty()) continue;
		ss.clear();
		deal_emphasis(tmp);
		while(deal_url(tmp));
		if(tmp[0] == '#')
		{
			ss<<tmp;
			ss>>t1;
			getline(ss,t2);

			cout<<"<h"<<t1.length()<<">";
			erase_blank(t2);
			cout<<t2<<"</h"<<t1.length()<<">\n";
			//<h1>Heading</h1>
		}
		else if(tmp[0] == '*')
		{
			tmp[0] = ' ';
			erase_blank(tmp);
			cout<<"<ul>\n"<<"<li>"<<tmp<<"</li>\n";

			while(getline(cin, tmp) && !tmp.empty())
			{
				deal_emphasis(tmp);
				while(deal_url(tmp));
				tmp[0] = ' ';
				erase_blank(tmp);
				cout<<"<li>"<<tmp<<"</li>\n";
			}
			cout<<"</ul>\n";
		}
		else
		{
			cout<<"<p>"<<tmp;
			while(getline(cin, tmp) && !tmp.empty())
			{
				deal_emphasis(tmp);
				while(deal_url(tmp));
				cout<<"\n"<<tmp;
			}
			cout<<"</p>\n";
		}
	}

	return 0;
}

/*

#  heading

##  sub-heading

paragraphs are separated
by a blank line.


test _italic_.

bullet list:

* apple
*   orange
* pear

[link](http://www.baidu.com).

_[link](http://www.baidu.com)_

*/