제출 #1175775

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1175775		totoro	Aliens (IOI16_aliens)	C++17	4 / 100	1 ms	328 KiB

aliens

// SOLVED SUBTASK 1   (04 pts)
// SOLVED SUBTASK 2   (12 pts)
// SOLVED SUBTASK 3   (09 pts)
// SOLVED SUBTASK 4   (16 pts)
// SOLVED SUBTASK 5   (19 pts)
// UNSOLVED SUBTASK 6 (40 pts)
// [+-+]----------------------
// TOTAL     60/100 pts

#include "aliens.h"

#include <algorithm>
#include <climits>
#include <cmath>
#include <iostream>
#include <vector>

struct Coordinate {
    long long row, col;
    Coordinate(long long row, long long col) : row(std::min(row, col)), col(std::max(row, col)) {}
    bool operator<(const Coordinate& other) const {
        if (row == other.row) {
            return col > other.col;
        }
        return row < other.row;
    }
};

struct Range {
    long long start, end;
    Range(long long start, long long end) : start(start), end(end) {};
    long long merge(const Range& other) const {
        return 2 * (other.start - start) * (other.end - end) - (other.start > end ? (other.start - end - 1) * (other.start - end - 1) : 0);
    }
};

struct Parabola {
    double h, v;

    double evaluate(double x) {
        return (x - h) * (x - h) + v;
    }
};

double intersect(Parabola a, Parabola b) {
    return (b.h * b.h + b.v - a.h * a.h - a.v) / (2.0 * (b.h - a.h));
}

struct ConvexHull {
    std::vector<Parabola> parabolas;
    std::vector<double> left, right;
    std::vector<int> indexes;
    int counter = 0;

    void insert(Parabola p) {
        while (!parabolas.empty() && intersect(p, parabolas.back()) <= left.back()) {
            parabolas.pop_back();
            left.pop_back();
            right.pop_back();
            indexes.pop_back();
        }
        if (parabolas.empty()) {
            parabolas.push_back(p);
            left.push_back(-1e18);  // neg infty
            right.push_back(1e18);  // infty
            indexes.push_back(counter);
        } else {
            double x = intersect(p, parabolas.back());
            right.back() = x;
            parabolas.push_back(p);
            left.push_back(x);
            right.push_back(1e18);  // infty
            indexes.push_back(counter);
        }
        ++counter;
        // std::cout << "inserted (x-" << p.h << ")^2 + " << p.v << '\n';
    }

    std::pair<int, double> min(double x) {
        int index = std::lower_bound(left.begin(), left.end(), x) - left.begin() - 1;
        return {indexes[index], parabolas[index].evaluate(x)};
    }
};

long long take_photos(int n, int m, int k, std::vector<int> r, std::vector<int> c) {
    std::vector<Coordinate> points;
    for (size_t i = 0; i < n; ++i) {
        points.push_back(Coordinate(r[i], c[i]));
    }
    std::sort(points.begin(), points.end());

    std::vector<Range> ranges;
    long long furthestStart = -1;
    long long furthestEnd = -1;
    for (size_t i = 0; i < points.size(); ++i) {
        Coordinate point = points[i];
        if (point.row > furthestStart && point.col > furthestEnd) {
            ranges.emplace_back(point.row, point.col);
            furthestStart = point.row;
            furthestEnd = point.col;
        }
    }
    ranges.push_back({(long long)1e15, (long long)1e15});

    long long lo = -1e10, hi = 1e10;
    long long anss = 0, cntt = 0;
    while (lo < hi) {
        long long penalty = std::floor((lo + hi) / 2.0);
        ConvexHull hull;
        std::vector<long long> ans;
        std::vector<long long> cnt;
        hull.insert(Parabola{(double)ranges[0].start, 0.0});
        ans.push_back(0), cnt.push_back(0);
        for (size_t range = 0; range < ranges.size() - 1; ++range) {
            // if (range == 0) {
            //     ans.push_back((ranges[range].end - ranges[0].start + 1) * (ranges[range].end - ranges[0].start + 1) + penalty);
            //     cnt.push_back(1);
            //     hull.insert(Parabola{(double)ranges[range + 1].start, (ranges[range].end - ranges[0].start + 1) * (ranges[range].end - ranges[0].start + 1) - std::pow(std::max(0ll, ranges[range].end - ranges[range + 1].start + 1), 2) + penalty});
            //     continue;
            // }

            auto [from, best] = hull.min(ranges[range].end + 1);
            hull.insert(Parabola{(double)ranges[range + 1].start, (double)best - std::pow(std::max(0ll, ranges[range].end - ranges[range + 1].start + 1), 2) + penalty});
            cnt.push_back(cnt[from] + 1);
            ans.push_back(best + penalty);
        }
        if (cnt.back() > k) {
            lo = penalty + 1;
        } else {
            hi = penalty;
            anss = ans.back();
            cntt = cnt.back();
        }
    }
    // std::cout << cntt << '\n';
    // std::cout << lo << '\n';
    return anss - cntt * lo;
}

컴파일 시 표준 에러 (stderr) 메시지

aliens.h:1:9: warning: #pragma once in main file
    1 | #pragma once
      |         ^~~~
aliens_c.h:1:9: warning: #pragma once in main file
    1 | #pragma once
      |         ^~~~

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