답안 #963063

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
963063	2024-04-14T12:42:52 Z	RaresFelix	Chorus (JOI23_chorus)	C++17	40 / 100	22 ms	1240 KB

chorus

#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;
      |                          ^~~

Subtask #1

16.0 / 16.0

#	결과	실행 시간	메모리	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

Subtask #2

24.0 / 24.0

#	결과	실행 시간	메모리	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

Subtask #3

0 / 21.0

#	결과	실행 시간	메모리	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	-

Subtask #4

0 / 26.0

#	결과	실행 시간	메모리	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	-

Subtask #5

0 / 13.0

#	결과	실행 시간	메모리	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	-