Submission #959713

#	Time	Username	Problem	Language	Result	Execution time	Memory
959713		ThegeekKnight16	Aliens (IOI16_aliens)	C++17	4 / 100	1 ms	432 KiB

aliens

#include <bits/stdc++.h>
#include "aliens.h"
using namespace std;
typedef long long ll;
vector<ll> A, B; int tam = 0, pos = 0;

bool inutil(int novo, int atual, int velho)
{
    return ((B[velho] - B[novo])*(A[atual] - A[velho]) <= (B[velho] - B[atual])*(A[novo] - A[velho]));
}

void update(int newA, int newB)
{
    A.push_back(newA); B.push_back(newB);
    ++tam;
    while (tam > 2 && inutil(tam-1, tam-2, tam-3)) {A.erase(A.end()-2); B.erase(B.end()-2); --tam;}
}

int query(int x)
{
    if (pos >= tam) pos = tam-1;
    while (pos < tam-1 && (A[pos]*x + B[pos]) >= (A[pos+1]*x + B[pos+1])) ++pos;
    return (A[pos]*x + B[pos]);
}

ll take_photos(int N, int M, int K, std::vector<int> r, std::vector<int> c)
{
    vector<pair<ll, ll>> v(N);
    for (int i = 0; i < N; i++)
    {
        int Y = r[i], X = c[i];
        if (X > Y) swap(X, Y);
        v[i] = make_pair(X, Y);
    }
    sort(v.begin(), v.end(), [&](const pair<int, int> &a, const pair<int, int> &b) {return (a.first == b.first ? a.second < b.second : a.first > b.first);});
    vector<pair<ll, ll>> pareto;
    for (auto [X, Y] : v)
    {
        while (!pareto.empty() && pareto.back().second <= Y) pareto.pop_back();
        pareto.emplace_back(X, Y);
    }
    v = pareto;
    reverse(v.begin(), v.end()); //So pra ficar ordenado por X
    N = v.size(); v.insert(v.begin(), make_pair(-1, -1));
    vector<ll> sIni(N+1), inter(N+1);
    for (int i = 1; i < N; i++) inter[i] = (v[i+1].first > v[i].second ? 0 : (v[i].second - v[i+1].first + 1)*(v[i].second - v[i+1].first + 1));
    for (int i = 1; i <= N; i++) sIni[i] = (v[i].second - v[i].first + 1)*(v[i].second - v[i].first + 1) + sIni[i-1] - inter[i-1];
    //Ate aqui estou so reduzindo o problema

    auto C = [&](int l, int r) {return ((v[r].second - v[l].first + 1LL) * (v[r].second - v[l].first + 1LL)) - (sIni[r] - sIni[l-1] + inter[l-1]);};

    vector<vector<ll>> dp(N+1, vector<ll>(K+1, 0x3f3f3f3f3f3f3f3f));
    fill(dp[0].begin(), dp[0].end(), 0);
    for (int k = 1; k <= K; k++)
    {
        A.clear(); B.clear(); tam = pos = 0;
        for (int i = 1; i <= N; i++)
        {
            update(-2*v[i].second, (v[i].second*v[i].second) + 2*v[i].second + sIni[i-1] - inter[i-1] + dp[i-1][k-1]);
            if (i <= k) {dp[i][k] = 0; continue;}
            dp[i][k] = ((v[i].first - 1)*(v[i].first - 1)) - sIni[i] + query(v[i].first);
        }
    }

    return dp[N][K] + sIni[N];
}

Compilation message (stderr)

aliens.cpp: In function 'll take_photos(int, int, int, std::vector<int>, std::vector<int>)':
aliens.cpp:50:10: warning: variable 'C' set but not used [-Wunused-but-set-variable]
   50 |     auto C = [&](int l, int r) {return ((v[r].second - v[l].first + 1LL) * (v[r].second - v[l].first + 1LL)) - (sIni[r] - sIni[l-1] + inter[l-1]);};
      |          ^

• Subtask 1: 4 / 4
• Subtask 2: 0 / 12
• Subtask 3: 0 / 9
• Subtask 4: 0 / 16
• Subtask 5: 0 / 19
• Subtask 6: 0 / 40