SRM D1 512 : 512 SubFibonacci

#include <algorithm>
#include <iostream>
#include <sstream>
#include <string>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <cstdio>
#include <cstdlib>
#include <cctype>
#include <cmath>
using namespace std;
typedef long long LL;
#define FOR(k,a,b) for(int k(a); k < (b); ++k)
#define REP(k,a) for(int k=0; k < (a); ++k)


class SubFibonacci {
    vector<LL> mS;
    vector<LL> fib;
    vector<pair<LL,LL> > fibpairs;
    map<LL,int> mMap;
    int n,m;
    int calc(int start,int end)
    {
        ++end;
        int res=2;
        FOR(i,start,end)
        FOR(j,start,end)
        if(i!=j)
        {
            FOR(k,0,2)
            FOR(l,0,m)
            // fibpairs[k].first*x+fibpairs[k].second*y = mS[i]
            // fibpairs[l].first*x+fibpairs[l].second*y = mS[j]
            if(k!=l)
            {
                LL x,y;
                if(k==0)
                {
                    x=mS[i];
                    y=(mS[j]-fibpairs[l].first*mS[i]);
                    if(y>0 && (y%fibpairs[l].second)==0)
                        y/=fibpairs[l].second;
                    else
                        continue;
                }
                if(k==1)
                {
                    y=mS[i];
                    x=mS[j]-fibpairs[l].second*mS[i];
                    if(x>0 && (x%fibpairs[l].first==0))
                        x/=fibpairs[l].first;
                    else
                        continue;
                }
                LL ttmp,last=0;
                int tmpres=0;
                REP(ttt,fibpairs.size())
                {
                    ttmp=fibpairs[ttt].first*x+fibpairs[ttt].second*y;
                    if (mMap.count(ttmp) && mMap[ttmp]>=start && mMap[ttmp]<end && ttmp>last)
                    {
                        ++tmpres;
                        last=ttmp;
                    }
                }
                if (tmpres>res)
                    res=tmpres;

            }
        }
        return res;
    }
public:
    int maxElements(vector <int> S) {
        sort(S.begin(),S.end());
        n=S.size();
        mS.resize(n);
        REP(i,n)
        {
            mS[i]=S[i];
            mMap[S[i]]=i;
        }
        const LL mMax=100000001;

        int res=min(4,n);
        fib.resize(2,1);
        while(fib.back()<mMax)
            fib.push_back(fib[fib.size()-2]+fib[fib.size()-1]);
        m=fib.size();
        fibpairs.resize(m);
        fibpairs[0]=make_pair(1,0);
        fibpairs[1]=make_pair(0,1);
        FOR(i,2,m)
        {
            fibpairs[i]=make_pair(fib[i-2],fib[i-1]);
        }

        FOR(i,2,n-2)
        {
            int tmp=calc(0,i)+calc(i+1,n-1);
            if (tmp>res)
                res=tmp;
        }
        return res;
    }

};