topcoder srm 144 div1 BinaryCode

这道题作为300分的水题，直接暴力就可以过了，题意是给你一个01串s，可以通过t[i] =s[i-1] + s[i]+ s[i+1]，得到一个新串t，

其中t[0] = s[0] + s[1],t[n-1] = t[n-1]+t[n-2]。我们现在输入的是串t，要求出串s。

下面贴代码:

#include <iostream>
#include <vector>
#include <string>
#include <cstdlib>
using namespace std;

class BinaryCode
{
        private:
                vector<string> data[50];
        public:
                vector<string> decode(string val)
                {
                        memset(data,0,sizeof(data));
                        inits(val);
                        string res;
                        vector<string> buf;
                        int k;
                        for(int i=0;i<data[0].size();i++)
                        {
                                res = data[0][i];
                                for(int j=1;j<val.length();j++)
                                {
                                        for(k=0;k<data[j].size();k++)
                                                if(cmp(res,data[j][k]))
                                                {
                                                        res.insert(res.length(),1,data[j][k][2]);
                                                        break;
                                                }
                                        if(k == data[j].size())
                                                break;
                                }
//                              cout << res << endl;
                                if(res.length() == val.length()+2)
                                        buf.push_back(res);
                        }
                        if(buf.size() == 0)
                                buf.push_back("NONE");
                        if(buf.size() == 1)
                                buf.push_back("NONE");
                        if(buf[0][1] != '1' && buf[1][1] != '0')
                        {
                                if(buf[0][0] != 'N')
                                        buf[0] = buf[0].substr(1,val.length());
                                if(buf[1][0] != 'N')
                                        buf[1] = buf[1].substr(1,val.length());
                                return buf;
                        }
                        else
                        {
                                string temp = buf[0]; 
                                buf[0] = buf[1]; 
                                buf[1] = temp; 
                        }
                        if(buf[0][0] != 'N')
                                buf[0] = buf[0].substr(1,val.length());
                        if(buf[1][0] != 'N')
                                buf[1] = buf[1].substr(1,val.length());
                        return buf;
                }
                void inits(string val)
                {
                        for(int i=0;i<val.length();i++)
                                if(val[i] == '0')
                                        this->data[i].push_back("000");
                                else if(val[i] == '1')
                                {
                                        if(i!=val.length()-1)
                                                data[i].push_back("001");
                                        data[i].push_back("010");
                                        if(i!=0)
                                                data[i].push_back("100");
                                }
                                else if(val[i] == '2')
                                {
                                        if(i!=0)
                                                data[i].push_back("110");
                                        if(i!=val.length()-1 && i != 0)
                                                data[i].push_back("101");
                                        if(i!=val.length()-1)
                                                data[i].push_back("011");
                                }
                                else if(i!=val.length()-1 && i!=0)
                                        data[i].push_back("111");
                }
                bool cmp(string s1,string s2)
                {
                        if(s1[s1.length()-2] == s2[0] && s1[s1.length()-1] == s2[1])
                                return true;
                        return false;
                }
};
 /*
int main()
{
        BinaryCode a;
        string s;
        cin >> s;
        vector<string> t = a.decode(s);
        cout << t[0] << " " << t[1] << endl;
        return 0;
}
*/