Submission #963063

# Submission time Handle Problem Language Result Execution time Memory
963063 2024-04-14T12:42:52 Z RaresFelix Chorus (JOI23_chorus) C++17
40 / 100
22 ms 1240 KB
#include <bits/stdc++.h>
#pragma GCC optimize("O3")
#pragma GCC target("avx,avx2,fma")

#define sz(x) int((x).size())
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()

using namespace std;
using ll = long long;
using ld = long double;  // or double, if TL is tight
using str = string; 
using ii = pair<int, int>;
using pl = pair<ll, ll>;
using vi = vector<int>;
using vll = vector<ll>;

const ll INF = 1e18;

struct CHT {
    int p = 0;
    vector<pair<ll, ll> > V;
    void insert(ll a, ll b) { /// ax + b
        //a va scadea mereu
        while(V.size() > 1) {
            auto [a1, b1] = V.end()[-1];
            auto [a2, b2] = V.end()[-2];
            if((b2 - b) * (a1 - a2) <= (b2 - b1) * (a - a2)) {
                V.pop_back();
                p = min(p, int(V.size()) - 1);
            }
            else break;
        }
        V.push_back({a, b});
    }

    ll query(ll x) {
        if(V.empty()) return INF;
        ll re = INF;
        auto eval = [&](int i) -> ll {
            return V[i].first * x + V[i].second;
        };
        while(p + 1 < V.size() && eval(p + 1) < eval(p)) ++p;
        return min(eval(p), INF);
    }
};

int main() {
    cin.tie(0);
    ios_base::sync_with_stdio(0);

    int n, k;
    cin >> n >> k;

    string s0, s;
    cin >> s0;
    ll re0 = 0;
    int nrB = 0, sum = 0;
    for(auto it : s0) {
        if(it == 'A') {
            ++sum;
            s += 'A';
            re0 += nrB;
            if(nrB && sum) {
                s += 'B';
                --nrB;
                --sum;
            }
        } else {
            if(sum) {
                s += 'B';
                --sum;
            } else {
                ++nrB;
            }
        }
    }

    vll A, P(n + 1);
    vll SA;
    P[0] = -1;
    for(auto it : s) {
        if(it == 'A'){
            A.push_back(nrB);
            if(SA.empty())
                SA.push_back(A.back());
            else
                SA.push_back(A.back() + SA.back());
        } 
        else {
            ++nrB;
            P[nrB] = (int)A.size() - 1;
        }
    }
    vll SAP(n);
    for(int i = 0; i < n; ++i) {
        SAP[i] = 0;
        if(P[i] != -1) SAP[i] = SA[P[i]];
    }

    auto cost = [&](ll st, ll dr) {
        return st * P[st] - SAP[st] + SA[dr] - st * dr;
    };


    auto t = [&](ll lambda) {
        ll re = - lambda * k;
        vll DP(n, INF);

        CHT Sol;

        for(int i = 0; i < n; ++i) {
            DP[i] = cost(0, i) + lambda;
            if(i)
                Sol.insert(-i, i * P[i] - SAP[i] + DP[i - 1]);
            DP[i] = min(DP[i], lambda + SA[i] + Sol.query(i));
        }

        return DP[n - 1] + re;
    };

    ll st = 0, dr = 1e6, mij;

    ll re = 0;
    for(int i = 0; i <= 100; ++i) {
        ll m1 = (2 * st + dr) / 3, v1 = t(m1);
        ll m2 = (st + 2 * dr) / 3, v2 = t(m2);
        re = max(re, v1);
        re = max(re, v2);
        if(st == dr) break;
        if(v1 > v2) dr = m2;
        else st = m1;
    }


    cout << re0 + re << "\n";
    return 0;
}

Compilation message

chorus.cpp: In member function 'll CHT::query(ll)':
chorus.cpp:43:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   43 |         while(p + 1 < V.size() && eval(p + 1) < eval(p)) ++p;
      |               ~~~~~~^~~~~~~~~~
chorus.cpp:39:12: warning: unused variable 're' [-Wunused-variable]
   39 |         ll re = INF;
      |            ^~
chorus.cpp: In function 'int main()':
chorus.cpp:122:26: warning: unused variable 'mij' [-Wunused-variable]
  122 |     ll st = 0, dr = 1e6, mij;
      |                          ^~~
# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 1 ms 504 KB Output is correct
5 Correct 0 ms 344 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 1 ms 348 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Correct 1 ms 344 KB Output is correct
13 Correct 0 ms 348 KB Output is correct
14 Correct 0 ms 344 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 0 ms 348 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 1 ms 504 KB Output is correct
5 Correct 0 ms 344 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 1 ms 348 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Correct 1 ms 344 KB Output is correct
13 Correct 0 ms 348 KB Output is correct
14 Correct 0 ms 344 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 0 ms 348 KB Output is correct
17 Correct 1 ms 348 KB Output is correct
18 Correct 2 ms 348 KB Output is correct
19 Correct 3 ms 344 KB Output is correct
20 Correct 1 ms 348 KB Output is correct
21 Correct 1 ms 348 KB Output is correct
22 Correct 1 ms 348 KB Output is correct
23 Correct 1 ms 348 KB Output is correct
24 Correct 2 ms 348 KB Output is correct
25 Correct 2 ms 348 KB Output is correct
26 Correct 2 ms 348 KB Output is correct
27 Correct 1 ms 348 KB Output is correct
28 Correct 2 ms 348 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 1 ms 504 KB Output is correct
5 Correct 0 ms 344 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 1 ms 348 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Correct 1 ms 344 KB Output is correct
13 Correct 0 ms 348 KB Output is correct
14 Correct 0 ms 344 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 0 ms 348 KB Output is correct
17 Correct 1 ms 348 KB Output is correct
18 Correct 2 ms 348 KB Output is correct
19 Correct 3 ms 344 KB Output is correct
20 Correct 1 ms 348 KB Output is correct
21 Correct 1 ms 348 KB Output is correct
22 Correct 1 ms 348 KB Output is correct
23 Correct 1 ms 348 KB Output is correct
24 Correct 2 ms 348 KB Output is correct
25 Correct 2 ms 348 KB Output is correct
26 Correct 2 ms 348 KB Output is correct
27 Correct 1 ms 348 KB Output is correct
28 Correct 2 ms 348 KB Output is correct
29 Correct 14 ms 1240 KB Output is correct
30 Correct 21 ms 604 KB Output is correct
31 Correct 22 ms 604 KB Output is correct
32 Incorrect 10 ms 604 KB Output isn't correct
33 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 1 ms 504 KB Output is correct
5 Correct 0 ms 344 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 1 ms 348 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Correct 1 ms 344 KB Output is correct
13 Correct 0 ms 348 KB Output is correct
14 Correct 0 ms 344 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 0 ms 348 KB Output is correct
17 Correct 1 ms 348 KB Output is correct
18 Correct 2 ms 348 KB Output is correct
19 Correct 3 ms 344 KB Output is correct
20 Correct 1 ms 348 KB Output is correct
21 Correct 1 ms 348 KB Output is correct
22 Correct 1 ms 348 KB Output is correct
23 Correct 1 ms 348 KB Output is correct
24 Correct 2 ms 348 KB Output is correct
25 Correct 2 ms 348 KB Output is correct
26 Correct 2 ms 348 KB Output is correct
27 Correct 1 ms 348 KB Output is correct
28 Correct 2 ms 348 KB Output is correct
29 Correct 14 ms 1240 KB Output is correct
30 Correct 21 ms 604 KB Output is correct
31 Correct 22 ms 604 KB Output is correct
32 Incorrect 10 ms 604 KB Output isn't correct
33 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 1 ms 504 KB Output is correct
5 Correct 0 ms 344 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 1 ms 348 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Correct 1 ms 344 KB Output is correct
13 Correct 0 ms 348 KB Output is correct
14 Correct 0 ms 344 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 0 ms 348 KB Output is correct
17 Correct 1 ms 348 KB Output is correct
18 Correct 2 ms 348 KB Output is correct
19 Correct 3 ms 344 KB Output is correct
20 Correct 1 ms 348 KB Output is correct
21 Correct 1 ms 348 KB Output is correct
22 Correct 1 ms 348 KB Output is correct
23 Correct 1 ms 348 KB Output is correct
24 Correct 2 ms 348 KB Output is correct
25 Correct 2 ms 348 KB Output is correct
26 Correct 2 ms 348 KB Output is correct
27 Correct 1 ms 348 KB Output is correct
28 Correct 2 ms 348 KB Output is correct
29 Correct 14 ms 1240 KB Output is correct
30 Correct 21 ms 604 KB Output is correct
31 Correct 22 ms 604 KB Output is correct
32 Incorrect 10 ms 604 KB Output isn't correct
33 Halted 0 ms 0 KB -