Submission #10,919

2024-04-18 21:54:18

cpp17

Accepted 100/100

98ms

30028 KiB

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
vector<int> p, r;
int n;
int get(int v)
{
    return p[v] == 0 ? v : p[v] = get(p[v]);
}
void unio(int a, int b)
{
    a = get(a);
    b = get(b);
    if(a != b)
    {
        if(r[a] < r[b]) swap(a, b);
        p[b] = a;
        if(r[a] == r[b]) r[a]++;
    }
}
struct val
{
    ll a, b, d;
};
bool cross(ll x1, ll y1, ll x2, ll y2)
{
    return x1 * y2 - x2 * y1 < 0;
}
bool insc(ll xa, ll xb, ll ya, ll yb)
{
    ll xd = 2e9 + 5, yd = 1, xc = 0, yc = 0;
    return (cross(xb - xa, yb - ya, xc - xa, yc - ya) != cross(xb - xa, yb - ya, xd - xa, yd - ya)) &&
        (cross(xd - xc, yd - yc, xa - xc, ya - yc) != cross(xd - xc, yd - yc, xb - xc, yb - yc));
}
int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cin >> n;
    p.resize(2 * n + 1);
    r.resize(2 * n + 1);
    vector<ll> x(n + 1), y(n + 1);
    vector<val> e;
    for(int i = 1; i <= n; i++)
    {
        cin >> x[i] >> y[i];
        for(int j = 1; j < i; j++)
        {
            ll dx = x[i] - x[j], dy = y[i] - y[j];
            e.push_back({j, i, dx * dx + dy * dy});
        }
    }
    sort(e.begin(), e.end(), [](val a, val b)
    {
        return a.d < b.d;
    });
    for(auto [a, b, d] : e)
    {
        bool g = insc(x[a], x[b], y[a], y[b]);
        //cout << a << " " << b << " " << d << " " << g << "\n";
        if(g)
        {
            unio(a, b + n);
            unio(a + n, b);
        }
        else
        {
            unio(a, b);
            unio(a + n, b + n);
        }
        if(get(a) == get(a + n))
        {
            cout << d << "\n";
            return 0;
        }
    }
    cout << "-1\n";
}

	Sum	Test	Verdict	Time	Memory
subtask1	0/0
		1	Accepted	3ms	1832 KiB
		2	Accepted	3ms	2024 KiB
subtask2	20/20
		3	Accepted	3ms	2240 KiB
		4	Accepted	3ms	2464 KiB
		5	Accepted	3ms	2556 KiB
		6	Accepted	3ms	2776 KiB
		7	Accepted	3ms	2984 KiB
		8	Accepted	3ms	3108 KiB
		9	Accepted	3ms	3336 KiB
		10	Accepted	3ms	3532 KiB
		11	Accepted	3ms	3616 KiB
		12	Accepted	3ms	3768 KiB
subtask3	20/20
		13	Accepted	3ms	2240 KiB
		14	Accepted	3ms	2464 KiB
		15	Accepted	3ms	2556 KiB
		16	Accepted	3ms	2776 KiB
		17	Accepted	3ms	2984 KiB
		18	Accepted	3ms	3108 KiB
		19	Accepted	3ms	3336 KiB
		20	Accepted	3ms	3532 KiB
		21	Accepted	3ms	3616 KiB
		22	Accepted	3ms	3768 KiB
		23	Accepted	3ms	4008 KiB
		24	Accepted	3ms	4096 KiB
		25	Accepted	3ms	4168 KiB
		26	Accepted	3ms	4292 KiB
		27	Accepted	3ms	4376 KiB
		28	Accepted	3ms	4376 KiB
		29	Accepted	3ms	4356 KiB
		30	Accepted	3ms	4444 KiB
		31	Accepted	3ms	4412 KiB
subtask4	20/20
		32	Accepted	3ms	2240 KiB
		33	Accepted	3ms	2464 KiB
		34	Accepted	3ms	2556 KiB
		35	Accepted	3ms	2776 KiB
		36	Accepted	3ms	2984 KiB
		37	Accepted	3ms	3108 KiB
		38	Accepted	3ms	3336 KiB
		39	Accepted	3ms	3532 KiB
		40	Accepted	3ms	3616 KiB
		41	Accepted	3ms	3768 KiB
		42	Accepted	3ms	4008 KiB
		43	Accepted	3ms	4096 KiB
		44	Accepted	3ms	4168 KiB
		45	Accepted	3ms	4292 KiB
		46	Accepted	3ms	4376 KiB
		47	Accepted	3ms	4376 KiB
		48	Accepted	3ms	4356 KiB
		49	Accepted	3ms	4444 KiB
		50	Accepted	3ms	4412 KiB
		51	Accepted	4ms	5040 KiB
		52	Accepted	3ms	5324 KiB
		53	Accepted	3ms	5280 KiB
		54	Accepted	3ms	5236 KiB
		55	Accepted	3ms	5228 KiB
		56	Accepted	3ms	5520 KiB
		57	Accepted	3ms	5488 KiB
		58	Accepted	3ms	5492 KiB
		59	Accepted	3ms	5512 KiB
		60	Accepted	3ms	5548 KiB
		61	Accepted	3ms	5500 KiB
		62	Accepted	3ms	5472 KiB
		63	Accepted	3ms	5472 KiB
		64	Accepted	3ms	5508 KiB
		65	Accepted	3ms	5416 KiB
		66	Accepted	3ms	5420 KiB
		67	Accepted	3ms	5672 KiB
		68	Accepted	3ms	5628 KiB
		69	Accepted	3ms	5656 KiB
		70	Accepted	3ms	5660 KiB
subtask5	40/40
		71	Accepted	3ms	2240 KiB
		72	Accepted	3ms	2464 KiB
		73	Accepted	3ms	2556 KiB
		74	Accepted	3ms	2776 KiB
		75	Accepted	3ms	2984 KiB
		76	Accepted	3ms	3108 KiB
		77	Accepted	3ms	3336 KiB
		78	Accepted	3ms	3532 KiB
		79	Accepted	3ms	3616 KiB
		80	Accepted	3ms	3768 KiB
		81	Accepted	3ms	4008 KiB
		82	Accepted	3ms	4096 KiB
		83	Accepted	3ms	4168 KiB
		84	Accepted	3ms	4292 KiB
		85	Accepted	3ms	4376 KiB
		86	Accepted	3ms	4376 KiB
		87	Accepted	3ms	4356 KiB
		88	Accepted	3ms	4444 KiB
		89	Accepted	3ms	4412 KiB
		90	Accepted	4ms	5040 KiB
		91	Accepted	3ms	5324 KiB
		92	Accepted	3ms	5280 KiB
		93	Accepted	3ms	5236 KiB
		94	Accepted	3ms	5228 KiB
		95	Accepted	3ms	5520 KiB
		96	Accepted	3ms	5488 KiB
		97	Accepted	3ms	5492 KiB
		98	Accepted	3ms	5512 KiB
		99	Accepted	3ms	5548 KiB
		100	Accepted	3ms	5500 KiB
		101	Accepted	3ms	5472 KiB
		102	Accepted	3ms	5472 KiB
		103	Accepted	3ms	5508 KiB
		104	Accepted	3ms	5416 KiB
		105	Accepted	3ms	5420 KiB
		106	Accepted	3ms	5672 KiB
		107	Accepted	3ms	5628 KiB
		108	Accepted	3ms	5656 KiB
		109	Accepted	3ms	5660 KiB
		110	Accepted	81ms	29864 KiB
		111	Accepted	85ms	29864 KiB
		112	Accepted	86ms	29872 KiB
		113	Accepted	86ms	29864 KiB
		114	Accepted	86ms	29868 KiB
		115	Accepted	81ms	29864 KiB
		116	Accepted	83ms	29936 KiB
		117	Accepted	83ms	30028 KiB
		118	Accepted	83ms	29936 KiB
		119	Accepted	86ms	29868 KiB
		120	Accepted	85ms	29868 KiB
		121	Accepted	85ms	29868 KiB
		122	Accepted	83ms	29868 KiB
		123	Accepted	85ms	29756 KiB
		124	Accepted	89ms	29940 KiB
		125	Accepted	85ms	29864 KiB
		126	Accepted	97ms	29868 KiB
		127	Accepted	92ms	29916 KiB
		128	Accepted	98ms	29868 KiB
		129	Accepted	90ms	29916 KiB
		130	Accepted	96ms	29964 KiB
		131	Accepted	75ms	29976 KiB
		132	Accepted	98ms	29944 KiB