제출 #588176

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
588176		georgievskiy	Aliens (IOI16_aliens)	C++17	60 / 100	2078 ms	15296 KiB

aliens

#include "aliens.h"
#include <bits/stdc++.h>
using namespace std;
#define int long long
#define ll long long
#define sqr(x) ((x)*(x))
using pii = pair<int, int>;
const int inf = 2e18;

struct line {
    int k, b;
    line() {
        k = 0, b = inf;
    }
    line(int k, int b) : k(k), b(b) {}
    int get(int x) {return k * x + b;}
};

double inter(line a, line b) {
    return 1.0 * (a.b - b.b) / (b.k - a.k);
}

vector<line> cht;
vector<double> xs;

void push(line t) {
    while (cht.size() && inter(cht.back(), t) < xs.back()) {
        cht.pop_back();
        xs.pop_back();
    }
    if (cht.size())
        xs.push_back(inter(cht.back(), t));
    else
        xs.push_back(-inf);
    cht.push_back(t);
}

int get(int x) {
    int ind = upper_bound(xs.begin(), xs.end(), x) - xs.begin() - 1;
    return cht[ind].get(x);
}

long long take_photos(signed n, signed m, signed k, std::vector<signed> r, std::vector<signed> c) {
    vector<pii> a(n);
    for (int i = 0; i < n; i++) a[i] = {max(r[i], c[i]), min(r[i], c[i])};
    sort(a.begin(), a.end(), [](pii a, pii b) {return a.first < b.first || a.first == b.first && a.second > b.second;});
    vector<pii> st;
    for (pii p : a) {
        while (st.size() && st.back().second >= p.second)
            st.pop_back();
        st.push_back(p);
    }
    n = st.size();
    k = min(k, n);
    m += 4;
    vector<int> x(n), y(n);
    for (int i = 0; i < n; i++)
        x[i] = st[i].first, y[i] = st[i].second;

    vector<int> t(n, 0);
    for (int i = 1; i < n; i++)
        t[i] = sqr(max(0ll, x[i - 1] - y[i] + 1));

    vector<int> cur(n + 1, inf);
    vector<line> lines;

    for (int j = 1; j <= k; j++) {
        cur[0] = 0;
        for (int i = 0; i < n; i++) {
            if (j == 1)
                cur[i + 1] = sqr(x[i] - y[0] + 1);
            else
                cur[i + 1] = get(x[i] + 1) + sqr(x[i] + 1);
            int k = -2 * y[i];
            int b = sqr(y[i]) - t[i] + cur[i];
            lines.push_back(line(k, b));
        }
        cht.clear(), xs.clear();
        for (line t : lines)
            push(t);
        lines.clear();
    }

    return cur.back();
}

컴파일 시 표준 에러 (stderr) 메시지

aliens.cpp: In lambda function:
aliens.cpp:46:95: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   46 |     sort(a.begin(), a.end(), [](pii a, pii b) {return a.first < b.first || a.first == b.first && a.second > b.second;});
      |                                                                            ~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

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