답안 #218775

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
218775 2020-04-02T17:42:03 Z gratus907 먼 별 (KOI16_dist) C++17
100 / 100
972 ms 4592 KB
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#define usecppio ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define all(x) ((x).begin()),((x).end())
#define int ll
using pii = pair <int, int>;
#define INF 0x7f7f7f7f7f7f7f7f
const bool debug = 0;
struct point
{
    int x, y, dx, dy;
    point operator+(const point &other)
    {
        return {x+other.x, y+other.y};
    }
    point operator-(const point &other)
    {
        return {x-other.x, y-other.y};
    }
    point operator*(const int C)
    {
        return {x*C, y*C, dx, dy};
    }
    int normsq()
    {
        return x*x+y*y;
    }
};

int dist(point &a, point &b)
{
    return (a-b).normsq();
}
class convex_hull
{
public:
    int n;
    static int ccw (point a, point b, point c)
    {
        int v = (b.x - a.x) * (c.y - a.y) - (b.y-a.y)*(c.x-a.x);
        if (v > 0) return 1;
        if (!v) return 0;
        return -1;
    }
    static bool compy (point &a, point &b)
    {
        if (a.y == b.y) return a.x < b.x;
        return a.y < b.y;
    }
    vector <point> pt;
    vector <point> convex;
    void graham_scan()
    {
        convex.clear();
        sort(all(pt), compy);
        point down = pt[0];
        sort(all(pt), [&down](auto a, auto b)
        {
            int u = ccw(down, a, b);
            if (u!=0) return u>0;
            else return dist(down, a) < dist(down, b);
        });
        convex.push_back(pt[0]);
        convex.push_back(pt[1]);
        for (int i = 2; i<n; i++)
        {
            while(convex.size() > 1)
            {
                point tp = convex.back();
                convex.pop_back();
                point tptp = convex.back();
                if (ccw(tptp,tp,pt[i]) > 0)
                {
                    convex.push_back(tp);
                    break;
                }
            }
            convex.push_back(pt[i]);
        }
    }
    int rotating_calipers()
    {
        int msz = 0;
        int t = 0;
        point o = {0, 0};
        int nc = convex.size();
        for(int i=0; i<convex.size(); i++)
        {
            while(t+1 < convex.size() && ccw(o, convex[i+1]-convex[i], convex[t+1]-convex[t])>=0)
            {
                if (msz < dist(convex[i], convex[t]))
                    msz = dist(convex[i], convex[t]);
                t++;
            }
            if (msz < dist(convex[i], convex[t]))
                msz = dist(convex[i], convex[t]);
        }
        return msz;
    }
};

convex_hull C;
vector <point> ptt;
int n, t;
int func(int x)
{
    C.pt.clear();
    for (int i = 0; i<n; i++)
        C.pt.push_back({ptt[i].x+ptt[i].dx*x, ptt[i].y+ptt[i].dy*x,0,0});
    C.graham_scan();
    int u = C.rotating_calipers();
    return u;
}
int32_t main()
{
    usecppio
    cin >> n >> t;
    C.n = n;
    for (int i = 0; i<n; i++)
    {
        int a, b, c, d;
        cin >> a >> b >> c >> d;
        ptt.push_back({a, b, c, d});
    }
    int lo = 0, hi = t;
    while(lo + 3 <= hi)
    {
        int m1 = (2*lo+hi)/3;
        int m2 = (lo+2*hi)/3;
        if (func(m1) > func(m2))
            lo = m1;
        else hi = m2;
    }
    int ind = lo;
    int best = func(lo);
    for (int i = lo; i<=hi; i++)
    {
        int cur = func(i);
        if (cur < best)
        {
            best = cur;
            ind = i;
        }
    }
    cout << ind << '\n';
    cout << best << '\n';
}

Compilation message

dist.cpp: In member function 'long long int convex_hull::rotating_calipers()':
dist.cpp:92:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int i=0; i<convex.size(); i++)
                      ~^~~~~~~~~~~~~~
dist.cpp:94:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             while(t+1 < convex.size() && ccw(o, convex[i+1]-convex[i], convex[t+1]-convex[t])>=0)
                   ~~~~^~~~~~~~~~~~~~~
dist.cpp:91:13: warning: unused variable 'nc' [-Wunused-variable]
         int nc = convex.size();
             ^~
# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 384 KB Output is correct
2 Correct 4 ms 384 KB Output is correct
3 Correct 4 ms 384 KB Output is correct
4 Correct 4 ms 384 KB Output is correct
5 Correct 4 ms 384 KB Output is correct
6 Correct 4 ms 384 KB Output is correct
7 Correct 4 ms 384 KB Output is correct
8 Correct 4 ms 384 KB Output is correct
9 Correct 4 ms 384 KB Output is correct
10 Correct 5 ms 256 KB Output is correct
# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 384 KB Output is correct
2 Correct 4 ms 384 KB Output is correct
3 Correct 4 ms 384 KB Output is correct
4 Correct 4 ms 384 KB Output is correct
5 Correct 4 ms 384 KB Output is correct
6 Correct 4 ms 384 KB Output is correct
7 Correct 4 ms 384 KB Output is correct
8 Correct 4 ms 384 KB Output is correct
9 Correct 4 ms 384 KB Output is correct
10 Correct 5 ms 256 KB Output is correct
11 Correct 24 ms 384 KB Output is correct
12 Correct 24 ms 512 KB Output is correct
13 Correct 23 ms 384 KB Output is correct
14 Correct 24 ms 384 KB Output is correct
15 Correct 26 ms 384 KB Output is correct
16 Correct 21 ms 512 KB Output is correct
17 Correct 23 ms 384 KB Output is correct
18 Correct 19 ms 512 KB Output is correct
19 Correct 22 ms 504 KB Output is correct
20 Correct 25 ms 384 KB Output is correct
# 결과 실행 시간 메모리 Grader output
1 Correct 208 ms 2808 KB Output is correct
2 Correct 188 ms 2808 KB Output is correct
3 Correct 191 ms 2808 KB Output is correct
4 Correct 142 ms 3696 KB Output is correct
5 Correct 230 ms 2808 KB Output is correct
6 Correct 160 ms 3832 KB Output is correct
7 Correct 164 ms 2764 KB Output is correct
8 Correct 153 ms 2808 KB Output is correct
9 Correct 163 ms 3828 KB Output is correct
10 Correct 204 ms 2936 KB Output is correct
# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 384 KB Output is correct
2 Correct 4 ms 384 KB Output is correct
3 Correct 4 ms 384 KB Output is correct
4 Correct 4 ms 384 KB Output is correct
5 Correct 4 ms 384 KB Output is correct
6 Correct 4 ms 384 KB Output is correct
7 Correct 4 ms 384 KB Output is correct
8 Correct 4 ms 384 KB Output is correct
9 Correct 4 ms 384 KB Output is correct
10 Correct 5 ms 256 KB Output is correct
11 Correct 24 ms 384 KB Output is correct
12 Correct 24 ms 512 KB Output is correct
13 Correct 23 ms 384 KB Output is correct
14 Correct 24 ms 384 KB Output is correct
15 Correct 26 ms 384 KB Output is correct
16 Correct 21 ms 512 KB Output is correct
17 Correct 23 ms 384 KB Output is correct
18 Correct 19 ms 512 KB Output is correct
19 Correct 22 ms 504 KB Output is correct
20 Correct 25 ms 384 KB Output is correct
21 Correct 208 ms 2808 KB Output is correct
22 Correct 188 ms 2808 KB Output is correct
23 Correct 191 ms 2808 KB Output is correct
24 Correct 142 ms 3696 KB Output is correct
25 Correct 230 ms 2808 KB Output is correct
26 Correct 160 ms 3832 KB Output is correct
27 Correct 164 ms 2764 KB Output is correct
28 Correct 153 ms 2808 KB Output is correct
29 Correct 163 ms 3828 KB Output is correct
30 Correct 204 ms 2936 KB Output is correct
31 Correct 914 ms 2936 KB Output is correct
32 Correct 854 ms 2936 KB Output is correct
33 Correct 848 ms 2936 KB Output is correct
34 Correct 830 ms 2936 KB Output is correct
35 Correct 972 ms 2936 KB Output is correct
36 Correct 749 ms 3944 KB Output is correct
37 Correct 803 ms 2928 KB Output is correct
38 Correct 636 ms 2936 KB Output is correct
39 Correct 647 ms 2936 KB Output is correct
40 Correct 865 ms 2928 KB Output is correct
41 Correct 725 ms 3824 KB Output is correct
42 Correct 829 ms 4592 KB Output is correct