uva10564

路径条数很好找。记录最小路径，就记录到各点的最小字符串，存储起来。

#include <iostream>
#include <cstdio>
#include <cmath>
#include <algorithm>
#include <vector>
#include <iomanip>
#include <cstring>
#include <map>
#include <queue>
#include <set>
#include <cassert>
#include <stack>
#include <bitset>
#define mkp make_pair
using namespace std;
const double EPS=1e-;
typedef long long lon;
const lon SZ=,INF=0x7FFFFFFF,mod=;
lon n,k,arr[SZ][SZ],dp[SZ][SZ][];
string str[SZ][SZ][];

void init()
{
    memset(dp,,sizeof(dp));
    for(int i=;i<=*n-;++i)
    {
        for(lon j=;j<=abs(n-i)+;++j)
        {
            cin>>arr[i][j];
        }
    }
    for(lon j=;j<SZ;++j)
    {
        if(j&)dp[][j][]=;
    }
}

string toStr(lon x)
{
    if(x==)return "";
    string res="";
    for(;x;)
    {
        res+=''+x%;
        x/=;
    }
    reverse(res.begin(),res.end());
    return res;
}

bool cmp(const string &x,const string &y)
{
    int pos1=x.find(" ");
    int pos2=y.find(" ");
    if(pos1!=pos2)return pos1<pos2;
    else return x<y;
}

void work()
{
    for(lon i=;i<=*n-;++i)
    {
        for(lon j=;j<=abs(n-i)+;++j)
        {
            lon cur=arr[i][j];
            for(lon p=arr[i][j];p<=k;++p)
            {
                if(i<=n)
                {
                    dp[i][j][p]+=dp[i-][j][p-cur];
                    dp[i][j][p]+=dp[i-][j+][p-cur];
                    if(i==)
                    {
                        str[i][j][p]=toStr(j-)+" ";
                    }
                    else if(dp[i-][j][p-cur]&&dp[i-][j+][p-cur])
                    {
                        if(cmp(str[i-][j][p-cur],str[i-][j+][p-cur]))
                        {
                            str[i][j][p]=str[i-][j][p-cur]+"R";
                        }
                        else
                        {
                            str[i][j][p]=str[i-][j+][p-cur]+"L";
                        }
                    }
                    else if(dp[i-][j][p-cur])
                    {
                        str[i][j][p]=str[i-][j][p-cur]+"R";
                    }
                    else if(dp[i-][j+][p-cur])
                    {
                        str[i][j][p]=str[i-][j+][p-cur]+"L";
                    }
                }
                else
                {
                    dp[i][j][p]+=dp[i-][j-][p-cur];
                    dp[i][j][p]+=dp[i-][j][p-cur];
                    if(i==)
                    {
                        str[i][j][p]=toStr(j-)+" ";
                    }
                    else if(dp[i-][j-][p-cur]&&dp[i-][j][p-cur])
                    {
                        if(cmp(str[i-][j-][p-cur],str[i-][j][p-cur]))
                        {
                            str[i][j][p]=str[i-][j-][p-cur]+"R";
                        }
                        else
                        {
                            str[i][j][p]=str[i-][j][p-cur]+"L";
                        }
                    }
                    else if(dp[i-][j-][p-cur])
                    {
                        str[i][j][p]=str[i-][j-][p-cur]+"R";
                    }
                    else if(dp[i-][j][p-cur])
                    {
                        str[i][j][p]=str[i-][j][p-cur]+"L";
                    }
                }
            }
        }
    }
    lon res=;
    char tmp=(char)(''+);
    string minstr="~~~~~~ ";
    for(lon j=;j<=n;++j)
    {
        res+=dp[*n-][j][k];
        if(dp[*n-][j][k])
        {
            //cout<<" "<<str[2*n-1][j][k]<<" "<<(str[2*n-1][j][k]=="")<<endl;
            minstr=min(minstr,str[*n-][j][k],cmp);
        }
    }
    cout<<res<<endl;
    if(res)cout<<minstr<<endl;
    else cout<<endl;
}

int main()
{
    std::ios::sync_with_stdio();
    //freopen("d:\\1.txt","r",stdin);
    lon casenum;
    //cin>>casenum;
    //cout<<casenum<<endl;
    //for(lon time=1;time<=casenum;++time)
    for(lon time=;cin>>n>>k,n;++time)
    {
        init();
        work();
    }
    return ;
}