Submission #582323

#	Time	Username	Problem	Language	Result	Execution time	Memory
582323		wiwiho	Uplifting Excursion (BOI22_vault)	C++17	0 / 100	52 ms	596 KiB

vault

#include <bits/stdc++.h>
#include <bits/extc++.h>

#define StarBurstStream ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define iter(a) a.begin(), a.end()
#define riter(a) a.rbegin(), a.rend()
#define lsort(a) sort(iter(a))
#define gsort(a) sort(riter(a))
#define pb(a) push_back(a)
#define eb(a) emplace_back(a)
#define pf(a) push_front(a)
#define ef(a) emplace_front(a)
#define pob pop_back()
#define pof pop_front()
#define mp(a, b) make_pair(a, b)
#define F first
#define S second
#define mt make_tuple
#define gt(t, i) get<i>(t)
#define tomax(a, b) ((a) = max((a), (b)))
#define tomin(a, b) ((a) = min((a), (b)))
#define topos(a) ((a) = (((a) % MOD + MOD) % MOD))
#define uni(a) a.resize(unique(iter(a)) - a.begin())
#define printv(a, b) {bool pvaspace=false; \
for(auto pva : a){ \
    if(pvaspace) b << " "; pvaspace=true;\
    b << pva;\
}\
b << "\n";}

using namespace std;
using namespace __gnu_pbds;

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;

using pii = pair<int, int>;
using pll = pair<ll, ll>;
using pdd = pair<ld, ld>;
using tiii = tuple<int, int, int>;

const ll MOD = 1000000007;
const ll MAX = 2147483647;

template<typename A, typename B>
ostream& operator<<(ostream& o, pair<A, B> p){
    return o << '(' << p.F << ',' << p.S << ')';
}

ll ifloor(ll a, ll b){
    if(b < 0) a *= -1, b *= -1;
    if(a < 0) return (a - b + 1) / b;
    else return a / b;
}

ll iceil(ll a, ll b){
    if(b < 0) a *= -1, b *= -1;
    if(a > 0) return (a + b - 1) / b;
    else return a / b;
}

int M;
int S;
ll L;
vector<ll> dp;

void waassert(bool t){
    return;
    if(t) return;
    cout << "OAO\n";
    exit(0);
}

void upd_pos(int sz, ll cnt, int t){
    if(cnt == 0) return;
    waassert(sz > 0 && cnt > 0);
    assert(t == 1);
    vector<deque<pll>> dq(sz);
    for(int i = 0; i <= 2 * S; i++){
        int id = i % sz;
        ll tmp = dp[i] - i / sz * t;
        while(!dq[id].empty() && dq[id].back().S <= tmp) dq[id].pob;
        dq[id].eb(mp(i, tmp));
        while(!dq[id].empty() && dq[id].front().F / sz < i / sz - cnt) dq[id].pof;
        dp[i] = max(dp[i], dq[id].front().S + i / sz * t);
    }
    /*cerr << "upd_pos " << sz << " " << cnt << "\n";
    printv(dp, cerr);*/
}

void upd_neg(int sz, ll cnt, int t){
    if(cnt == 0) return;
    waassert(sz > 0 && cnt > 0);
    assert(t == 1);
    vector<deque<pll>> dq(sz);
    for(int i = 2 * S; i >= 0; i--){
        int id = i % sz;
        ll tmp = dp[i] + i / sz * t;
        while(!dq[id].empty() && dq[id].back().S <= tmp) dq[id].pob;
        dq[id].eb(mp(i, tmp));
        while(!dq[id].empty() && dq[id].front().F / sz > i / sz + cnt) dq[id].pof;
        dp[i] = max(dp[i], dq[id].front().S - i / sz * t);
    }
    /*cerr << "upd_neg " << sz << " " << cnt << "\n";
    printv(dp, cerr);*/
}

int main(){
    StarBurstStream

    cin >> M;
    cin >> L;
    
    ll sum = 0;
    vector<ll> _a(2 * M + 1), _b(2 * M + 1);
    function<ll&(int)> a = [&](int x) -> ll&{
        waassert(M + x >= 0 && M + x <= 2 * M);
        return _a[M + x];
    };
    function<ll&(int)> b = [&](int x) -> ll&{
        waassert(M + x >= 0 && M + x <= 2 * M);
        return _b[M + x];
    };
    for(int i = -M; i <= M; i++){
        cin >> a(i);
        sum += a(i) * i;
    }

    if(sum <= L){
        for(int i = -M; i < 0; i++){
            swap(a(i), a(-i));
        }
        L = -L;
    }

    int p = -M - 1;
    sum = 0;
    for(int i = -M; i <= M; i++){
        sum += a(i) * i;
        if(sum <= L) p = i;
    }
    sum = 0;
    ll total = 0;
    /*for(int i = -M; i <= p; i++){
        sum += a(i) * i;
        b(i) = a(i);
        total += b(i);
    }
    if(p < M){
        b(p + 1) = (L - sum) / (p + 1);
        sum += b(p + 1) * (p + 1);
        total += b(p + 1);
    }*/
    total = a(0);

    /*cerr << "test " << sum << " " << L << " " << L - sum << "\n";
    printv(_a, cerr);
    printv(_b, cerr);*/

    S = max(M * M, 10000);
    dp.resize(2 * S + 1, -(1LL << 60));
    dp[S] = 0;

    //printv(dp, cerr);
    for(int i = -M; i <= M; i++){
        if(i == 0) continue;
        if(i < 0){
            upd_pos(-i, b(i), -1);
            upd_neg(-i, a(i) - b(i), 1);
        }
        else{
            upd_pos(i, a(i) - b(i), 1);
            upd_neg(i, b(i), -1);
        }
    }

    ll ans = L - sum > S || L - sum < -S ? -(1LL << 60) : dp[S + L - sum];
    if(ans < -1e9) cout << "impossible\n";
    else cout << total + ans << "\n";

    return 0;
}

Compilation message (stderr)

vault.cpp: In function 'int main()':
vault.cpp:137:9: warning: variable 'p' set but not used [-Wunused-but-set-variable]
  137 |     int p = -M - 1;
      |         ^

• Subtask 1: 0 / 5
• Subtask 2: 0 / 15
• Subtask 3-1: 0 / 10
• Subtask 3-2: 0 / 10
• Subtask 4-1: 0 / 10
• Subtask 4-2: 0 / 10
• Subtask 5-1: 0 / 10
• Subtask 5-2: 0 / 10
• Subtask 6-1: 0 / 10
• Subtask 6-2: 0 / 10