Submission #1070304

#	Time	Username	Problem	Language	Result	Execution time	Memory
1070304		GrindMachine	Tricks of the Trade (CEOI23_trade)	C++17	50 / 100	2530 ms	21428 KiB

trade

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) (int)a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x,y) ((x+y-1)/(y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl

#define rep(i,n) for(int i = 0; i < n; ++i)
#define rep1(i,n) for(int i = 1; i <= n; ++i)
#define rev(i,s,e) for(int i = s; i >= e; --i)
#define trav(i,a) for(auto &i : a)

template<typename T>
void amin(T &a, T b) {
    a = min(a,b);
}

template<typename T>
void amax(T &a, T b) {
    a = max(a,b);
}

#ifdef LOCAL
#include "debug.h"
#else
#define debug(...) 42
#endif

/*

refs:
edi

*/

const int MOD = 1e9 + 7;
const int N = 1e5 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;

void solve(int test_case)
{
    ll n,k; cin >> n >> k;
    vector<ll> a(n+5), b(n+5);
    rep1(i,n) cin >> a[i];
    rep1(i,n) cin >> b[i]; 
    vector<ll> p(n+5);
    rep1(i,n) p[i] = p[i-1]+a[i];

    multiset<ll> ms1,ms2;
    ll curr_sum = 0;
    ll lx = 1, rx = 0;

    auto transfer = [&](){
        while(!ms2.empty() and sz(ms1) < k){
            curr_sum += *ms2.rbegin();
            ms1.insert(*ms2.rbegin());
            ms2.erase(--ms2.end());
        }

        while(sz(ms1) > k){
            ll x = *ms1.begin();
            curr_sum -= x;
            ms1.erase(ms1.begin());
            ms2.insert(x);
        }

        if(ms2.empty()) return;

        while(true){
            ll mn1 = *ms1.begin(), mx2 = *ms2.rbegin();
            if(mn1 >= mx2) break;
            ms1.erase(ms1.find(mn1));
            ms2.erase(ms2.find(mx2));
            ms1.insert(mx2);
            ms2.insert(mn1);
            curr_sum += mx2-mn1;
        }
    };

    auto ins = [&](ll i){
        ms1.insert(b[i]);
        curr_sum += b[i];
        transfer();
    };

    auto del = [&](ll i){
        if(ms1.find(b[i]) != ms1.end()){
            ms1.erase(ms1.find(b[i]));
            curr_sum -= b[i];
        }
        else{
            ms2.erase(ms2.find(b[i]));
        }

        transfer();
    };

    auto f = [&](ll l, ll r){
        if(r-l+1 < k) return -inf2;
        
        // expand
        while(rx < r){
            rx++;
            ins(rx);
        }
        while(lx > l){
            lx--;
            ins(lx);
        }

        // contract
        while(rx > r){
            del(rx);
            rx--;
        }
        while(lx < l){
            del(lx);
            lx++;
        }

        ll sum = -(p[r]-p[l-1]);
        sum += curr_sum;
        return sum;
    };

    ll ans = -inf2;

    auto go = [&](ll l, ll r, ll optl, ll optr, auto &&go) -> void{
        if(l > r) return;
        ll mid = (l+r) >> 1;
        ll best = -inf2, optm = -1;

        for(int i = optl; i <= optr; ++i){
            ll cost = f(mid,i);
            if(cost >= best){
                best = cost;
                optm = i;
            }
        }

        amax(ans,best);

        go(l,mid-1,optl,optm,go);
        go(mid+1,r,optm,optr,go);
    };

    go(1,n-k+1,1,n,go);
    cout << ans << endl;
}

int main()
{
    fastio;

    int t = 1;
    // cin >> t;

    rep1(i, t) {
        solve(i);
    }

    return 0;
}

• Subtask 0: 0 / 0
• Subtask 1: 5 / 10
• Subtask 2: 5 / 10
• Subtask 3: 5 / 10
• Subtask 4: 10 / 25
• Subtask 5: 25 / 45