Codeforces round 1176(C. Lose it!)

 ///Bismillahir Rahmanir Rahim

///Author: Tanvir Ahmmad

///CSE,Islamic University,Bangladesh

#include<iostream>

#include<cstdio>

#include<algorithm>

#include<string>

#include<cstring>

#include<sstream>

#include<cmath>

#include<cstring>

#include<vector>

#include<queue>

#include<map>

#include<set>

#include<stack>

#include<vector>

#include<iterator>

#include <functional> ///sort(arr,arr+n,greater<int>()) for decrement of array

/*every external angle sum=360 degree

  angle find using polygon hand(n) ((n-2)*180)/n*/

///Floor[Log(b)  N] + 1 = the number of digits when any number is represented in base b

using namespace std;

typedef long long ll;

int main()

{

    ll n,check[]= {4,8,15,16,23,42},flag=0,base=0,num,last_8=0,last_15=0,last_16=0,last_23=0,last_42=0;

    vector<ll>vec[8];

    cin>>n;

    for(ll i=0; i<n; i++)

    {

        cin>>num;

        for(ll j=0; j<6; j++)

            if(num==check[j])

                vec[j].push_back(i);

    }

    for(ll i=0; i<vec[0].size() && flag==0; i++)

    {

        ll cur=vec[0][i],cnt=0;

        for(ll j=last_8 ; j<vec[1].size(); j++)

        {

            if(cur<vec[1][j])

            {

                cur=vec[1][j];

                last_8=j+1;

                cnt++;

                break;

            }

            if(j+1==vec[1].size())

                flag=1;

        }

        for(ll j=last_15; j<vec[2].size(); j++)

        {

            if(cur<vec[2][j])

            {

                cur=vec[2][j];

                last_15=j+1;

                cnt++;

                break;

            }

            if(j+1==vec[2].size())

                flag=1;

        }

        for(ll j=last_16; j<vec[3].size(); j++)

        {

            if(cur<vec[3][j])

            {

                cur=vec[3][j];

                last_16=j+1;

                cnt++;

                break;

            }

            if(j+1==vec[3].size())

                flag=1;

        }

        for(ll j=last_23; j<vec[4].size(); j++)

        {

            if(cur<vec[4][j])

            {

                cur=vec[4][j];

                last_23=j+1;

                cnt++;

                break;

            }

            if(j+1==vec[4].size())

                flag=1;

        }

        for(ll j=last_42; j<vec[5].size(); j++)

        {

            if(cur<vec[5][j])

            {

                cur=vec[5][j];

                last_42=j+1;

                cnt++;

                break;

            }

            if(j+1==vec[1].size())

                flag=1;

        }

        if(cnt==5)

            base++;

    }

    cout<<n-(base*6)<<endl;

    return 0;

}

///Alhamdulillah

Problem Link:https://codeforces.com/problemset/problem/1176/C