QOJ.ac

QOJ

IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#363260#8505. Almost Aligneducup-team3215#WA 380ms34412kbC++234.4kb2024-03-23 20:07:262024-03-23 20:07:26

Judging History

你现在查看的是最新测评结果

  • [2024-03-23 20:07:26]
  • 评测
  • 测评结果:WA
  • 用时:380ms
  • 内存:34412kb
  • [2024-03-23 20:07:26]
  • 提交

answer

#include <bits/stdc++.h>

using namespace std;
using ll = long long;
using ld = long double;
using pl = pair<ll, ll>;

constexpr ld INF = 1e17 + 1;

struct point {
    ll x, y, vx, vy;

    pair<ld, ld> eval(ld t) {
        return {x + t * vx, y + t * vy};
    }
};


struct Line {
    mutable ll k, m, p, id;

    bool operator<(const Line &o) const { return k < o.k; }

    bool operator<(ll x) const { return p < x; }
};

struct LineContainer : multiset<Line, less<>> {
    static constexpr ll inf = LLONG_MAX;

    ll div(ll a, ll b) { return a / b - ((a ^ b) < 0 && a % b); }

    bool isect(iterator x, iterator y) {
        if (y == end()) return x->p = inf, 0;
        if (x->k == y->k) x->p = x->m > y->m ? inf : -inf;
        else x->p = div(y->m - x->m, x->k - y->k);
        return x->p >= y->p;
    }

    void add(ll k, ll m, ll id) {
        if (count({k, m, 0, id}))return;
        auto z = insert({k, m, 0, id}), y = z++, x = y;
        while (isect(y, z)) z = erase(z);
        if (x != begin() && isect(--x, y)) isect(x, y = erase(y));
        while ((y = x) != begin() && (--x)->p >= y->p)
            isect(x, erase(y));
    }
};

struct rat {
    ll x, y;

    rat(ll x, ll y) : x(x), y(y) {
        ll g = __gcd(x, y);
        x /= g;
        y /= g;
        if (x * y < 0) {
            ll x = 214;
        }
    }

    auto operator<=>(const rat &) const = default;
};

int main() {
    cin.tie(0)->sync_with_stdio(false);
    ll n;
    cin >> n;
    vector<point> a(n);
    for (auto &[x, y, vx, vy]: a)cin >> x >> y >> vx >> vy;
    map<rat, vector<pair<point, ll>>> mp;
    {
        LineContainer z;
        for (ll i = 0; auto [x, y, vx, vy]: a) {
            z.add(vx, x, i++);
        }
        mp[rat(0, 1)].push_back({a[z.begin()->id], 0});
        auto last = a[z.begin()->id];
        z.erase(z.begin());
        while (!z.empty()) {
            auto it = a[z.begin()->id];
            z.erase(z.begin());
            assert(it.vx > last.vx);
            mp[rat(abs(last.x - it.x), abs(it.vx - last.vx))].push_back({it, 0});
            last = it;
        }
    }
    {
        LineContainer z;
        for (ll i = 0; auto [x, y, vx, vy]: a) {
            z.add(-vx, -x, i++);
        }
        mp[rat(0, 1)].push_back({a[z.begin()->id], 1});
        auto last = a[z.begin()->id];
        z.erase(z.begin());
        while (!z.empty()) {
            auto it = a[z.begin()->id];
            z.erase(z.begin());
            assert(it.vx < last.vx);
            mp[rat(abs(it.x - last.x), abs(last.vx - it.vx))].push_back({it, 1});
            last = it;
        }
    }
    {
        LineContainer z;
        for (ll i = 0; auto [x, y, vx, vy]: a) {
            z.add(vy, y, i++);
        }
        mp[rat(0, 1)].push_back({a[z.begin()->id], 2});
        auto last = a[z.begin()->id];
        z.erase(z.begin());
        while (!z.empty()) {
            auto it = a[z.begin()->id];
            z.erase(z.begin());
            assert(it.vy > last.vy);
            mp[rat(abs(last.y - it.y), abs(it.vy - last.vy))].push_back({it, 2});
            last = it;
        }
    }
    {
        LineContainer z;
        for (ll i = 0; auto [x, y, vx, vy]: a) {
            z.add(-vy, -y, i++);
        }
        mp[rat(0, 1)].push_back({a[z.begin()->id], 3});
        auto last = a[z.begin()->id];
        z.erase(z.begin());
        while (!z.empty()) {
            auto it = a[z.begin()->id];
            z.erase(z.begin());
            assert(it.vy < last.vy);
            mp[rat(abs(it.y - last.y), abs(last.vy - it.vy))].push_back({it, 3});
            last = it;
        }
    }
    ld res = 1e20;
    array<point, 4> cur;
    for (const auto &[t, v]: mp) {
        for (auto [p, i]: v) {
            cur[i] = p;
        }
        ld mnX = INF, mxX = -INF;
        ld mnY = INF, mxY = -INF;
        ld timer = (ld) t.x / t.y;
//        cout << timer << endl;
        for (auto p: cur) {
//            cout << p.x << " " << p.y << " " << p.vx << " " << p.vy << endl;
            auto [x, y] = p.eval(timer);
            mnX = min(mnX, x);
            mnY = min(mnY, y);
            mxX = max(mxX, x);
            mxY = max(mxY, y);
        }
        res = min(res,  (mxX - mnX) * (mxY - mnY));
    }
    cout << fixed << setprecision(20);
    cout << res;
    return 0;
}

Details

Tip: Click on the bar to expand more detailed information

Test #1:

score: 100
Accepted
time: 0ms
memory: 3784kb

input:

4
0 0 10 10
0 0 10 10
10 10 -10 -10
10 0 -20 0

output:

22.22222222222222222203

result:

ok found '22.222222222', expected '22.222222222', error '0.000000000'

Test #2:

score: 0
Accepted
time: 0ms
memory: 3800kb

input:

3
0 -1 0 2
1 1 1 1
-1 1 -1 1

output:

0.00000000000000000000

result:

ok found '0.000000000', expected '0.000000000', error '-0.000000000'

Test #3:

score: 0
Accepted
time: 0ms
memory: 3848kb

input:

3
0 -1 0 -2
1 1 1 1
-1 1 -1 1

output:

4.00000000000000000000

result:

ok found '4.000000000', expected '4.000000000', error '0.000000000'

Test #4:

score: 0
Accepted
time: 0ms
memory: 3840kb

input:

1
0 0 0 0

output:

0.00000000000000000000

result:

ok found '0.000000000', expected '0.000000000', error '-0.000000000'

Test #5:

score: 0
Accepted
time: 0ms
memory: 3844kb

input:

4
1000000 1000000 -1 -1000000
1000000 -1000000 -1000000 1
-1000000 -1000000 1 1000000
-1000000 1000000 1000000 -1

output:

3999984000031.99995207786560058594

result:

ok found '3999984000032.000000000', expected '3999984000032.000000000', error '0.000000000'

Test #6:

score: -100
Wrong Answer
time: 380ms
memory: 34412kb

input:

1000000
-871226 486657 -467526 31395
-65837 846554 469710 -907814
927993 -45099 713462 -276539
261942 483255 746021 811070
63449 -779486 588838 -413687
812070 -87868 -813499 -420768
112521 -622607 -832012 921368
-182120 517379 -401743 -837524
-685985 337832 643014 135144
12895 326935 -495720 930620
...

output:

2261287233698.57317018508911132812

result:

wrong answer 1st numbers differ - expected: '3999996000000.0000000', found: '2261287233698.5732422', error = '0.4346776'