1282C - Petya and Exam - CodeForces Solution

#include <iostream>
#include <algorithm>
#include <cmath>
#include <map>
#include <unordered_map>
#include <queue>
#include <set>
#include <vector>
#include <cstring>
#include <numeric>
#include <cassert>
#include <iomanip>
using namespace std;

using str =  string;
using ll  =  long long;
using ld  =  long double;
using vl  =  vector<ll>;
using vs  =  vector<str>;
using vpl =  vector<pair<ll,ll>>;
using sll =  set<ll>;
using pll =  pair<ll,ll>;
#define mset multiset
#define umap unordered_map

/*#include<ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
using iset = tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update>;
#define sAt(s,x) s.find_by_order(x) //Returns xth Iterator
#define sPos(s,x) s.order_of_key(x) //Return lower bound index*/

#define pus push_back
#define pub pop_back
#define in  insert
#define ff  first
#define ss  second

#define sz(x)     ((ll)(x).size())
#define all(x)    x.begin(),x.end()
#define srt(x)    sort(all(x))
#define srtd(x)   sort(x.rbegin(),x.rend())
#define rev(x)    reverse(all(x));
#define nextP(v)  next_permutation(all(v))
#define Vmax(x)   (*max_element(all(x)))
#define Vmin(x)   (*min_element(all(x)))
#define Vsum(x)   accumulate(all(x),0ll)
#define lowB(v,x) (lower_bound(all(v),x)-v.begin())
#define upB(v,x)  (upper_bound(all(v),x)-v.begin())
#define cntB(x)   (__builtin_popcountll(x))  
#define cntC(s,x) ll(count(all(s),x))

#define For(n)      for (ll i = 0; i < n; i++)
#define ForR(n)     for (ll i = n-1; i >= 0; i--)
#define Forj(n)     for (ll j = 0; j < n; j++)
#define For1(n)     for (ll i = 1; i < n; i++)
#define Forl(x,y,z) for (ll x = y; x < z; x++)

#define nl       cout << "\n";
#define endl     "\n";
#define ya       cout << "Yes\n"
#define na       cout << "No\n"
#define prs(n)   fixed << setprecision(n)
#define dbg(x)   cout << #x << " = " << x << endl;
#define inpt(v)  For(sz(v)) cin >> v[i];
#define prt(v)  {for(auto &x:v) cout << x << ' '; nl}

const int M = 1e9+7; /*998244353;*/
const int N = 2e5+5;
const ld pi = 3.141592653589793238;
const ll INF = 2e18;

ll power(ll a,ll b) {ll r=1; while(b) {if(b&1) r=(r*a)%M; a=(a*a)%M; b/=2;} return r;}
vl sieve(ll n) {vl a(n+1,1),v; a[0]=a[1]=0; Forl(i,2,n+1) if(a[i]) {v.pus(i); for(ll j=2*i; j <=n; j+=i) a[j]=0;} return a;}
vl divsr(ll n) {vl a(n+1,1); For(n+1) a[i]=i; Forl(i,2,n+1) if(a[i]==i) {for(ll j=2*i; j<=n; j+=i) a[j]=i;} return a;}
vl fac(ll n) {vl v(n+1,1); Forl(i,2,n+1) v[i] = (v[i-1]*i)%M; return v;}

ll n, x, y, z, a, b, c, d, k, q, m; str s; 
 
//---------------------------------------------------------------------------------------------------------------------------------
//Let's Go :)

void solve()
{
      cin >> n >> k >> a >> b;

      vpl p(n);
      ll ans = 0, ezy = 0, hrd = 0, thard = 0, teasy = 0;

      For(n) cin >> p[i].ss;
      For(n) cin >> p[i].ff;

      For(n) 
      if(p[i].ss) thard++;
      else teasy++;

      if(thard*b+teasy*a<=k)
      {
            cout << n; nl return;
      }

      srt(p);

      for(auto &pr:p)
      {
            ll var = pr.ff-1, cnt = hrd+ezy;

            var -= (hrd*b + ezy*a);

            if(var>=0) 
            {
                  x = var/a;
                  x = min(x,teasy);

                  cnt += x;
                  var -= x*a;

                  x = var/b;
                  x = min(x,thard);

                  cnt += x;
                  
                  ans = max(ans,cnt);
            }

            if(pr.ss) hrd++, thard--;
            else ezy++, teasy--;
      }

      cout << ans; nl
}

int main()
{
      ios_base::sync_with_stdio(0); cin.tie(0);
      int t = 1;
      cin >> t;
       
      while(t--) solve();

      return 0;
}