oj.uz

답안 #62320

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
62320 2018-07-28T05:05:14 Z Benq Fences (JOI18_fences) C++11
51 / 100
 547 ms 2396 KB 
#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>

using namespace std;
using namespace __gnu_pbds;
 
typedef long long ll;
typedef long double ld;
typedef complex<ld> cd;

typedef pair<int, int> pi;
typedef pair<ll,ll> pl;
typedef pair<ld,ld> pd;

typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<cd> vcd;

template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update>;

#define FOR(i, a, b) for (int i=a; i<(b); i++)
#define F0R(i, a) for (int i=0; i<(a); i++)
#define FORd(i,a,b) for (int i = (b)-1; i >= a; i--)
#define F0Rd(i,a) for (int i = (a)-1; i >= 0; i--)

#define sz(x) (int)(x).size()
#define mp make_pair
#define pb push_back
#define f first
#define s second
#define lb lower_bound
#define ub upper_bound
#define all(x) x.begin(), x.end()

const int MOD = 1000000007;
const ll INF = 1e18;
const int MX = 100001;

ld EPS = 1e-11;

template<class T> istream& operator>> (istream& is, complex<T>& p) {
    T value;
    is >> value; p.real(value);
    is >> value; p.imag(value);
    return is;
}

int N,S;
vector<pair<cd,cd>> p;
vector<vector<pair<int,ld>>> adj;
vector<ld> dist;
ld ans = INF;

cd reflect(cd p, cd a, cd b) { return a+conj((p-a)/(b-a))*(b-a); }
cd proj(cd p, cd a, cd b) { return (p+reflect(p,a,b))/(ld)2; }

bool bet(cd a, cd b, cd c) { return ((b-a)/(c-b)).real() > 0; }

cd closest(cd a, pair<cd,cd> b) {
    if (b.f == b.s) return b.f;
    auto x = proj(a,b.f,b.s);
    if (bet(b.f,x,b.s)) return x;
    return abs(a-b.f) < abs(a-b.s) ? b.f : b.s;
}

ld cross(cd a, cd b) { return (conj(a)*b).imag(); }
ld area(cd a, cd b, cd c) { return cross(b-a,c-a); }


cd line(cd a, cd b, cd c, cd d) {
    ld x = area(a,b,c), y = area(a,b,d);
    return (x*d-y*c)/(x-y);
}

bool equiv(cd a, cd b) {
    return abs(1-abs(a/b)) <= EPS;
}

int inter(pair<cd,cd> bes) {
    F0R(i,4) {
        auto x = line({0,0},p[i].f,bes.f,bes.s);
        if (bet(bes.f,x,bes.s) && abs(x) < abs(p[i].f) && !equiv(p[i].f,x)) return MOD;
    }
    bool swa = 0;
    if (bes.f.imag() > bes.s.imag()) swa = 1, swap(bes.f,bes.s);
    if (bes.f.imag() < 0 && bes.s.imag() >= 0) {
        auto x = line({0,0},{1,0},bes.f,bes.s);
        if (x.real() < 0) return 0;
        if (swa == 0) return 1;
        return -1;
    }
    return 0;
}

pair<cd,cd> bet(pair<cd,cd> a, pair<cd,cd> b) {
     return (abs(a.f-a.s) < abs(b.f-b.s) ? a : b);
}

pair<ld,int> dis(pair<cd,cd> a, pair<cd,cd> b) {
    pair<cd,cd> bes = {{0,0},{INF,INF}};
    bes = bet(bes,{a.f,closest(a.f,b)});
    bes = bet(bes,{a.s,closest(a.s,b)});
    bes = bet(bes,{closest(b.f,a),b.f});
    bes = bet(bes,{closest(b.s,a),b.s});
    
    int x = inter(bes);
    
    if (x == MOD) return {INF,0};
    return {abs(bes.s-bes.f),x};
}

void input() {
    ios_base::sync_with_stdio(0); cin.tie(0);
    cin >> N >> S;
    p.pb({{S,S},{S,S}});
    p.pb({{S,-S},{S,-S}});
    p.pb({{-S,S},{-S,S}});
    p.pb({{-S,-S},{-S,-S}});
    F0R(i,N) {
        cd a,b; cin >> a >> b;
        if (a.imag() > b.imag()) swap(a,b);
        if (a.imag() < 0 && b.imag() >= 0) {
            auto x = line(a,b,{0,0},{1,0});
            if (x.real() > 0) {
                p.pb({a,x+EPS*(a-x)});
                p.pb({x,b});
                continue;
            }
        } 
        p.pb({a,b});
    }
}

void genDist(int x) {
    dist.resize(3*sz(p)); F0R(i,3*sz(p)) dist[i] = INF;
    priority_queue<pair<ld,int>,vector<pair<ld,int>>,greater<pair<ld,int>>> p;
    p.push({dist[x] = 0, x});
    while (sz(p)) {
        auto a = p.top(); p.pop();
        if (a.f > dist[a.s]) continue;
        for (auto x: adj[a.s]) if (x.s+a.f < dist[x.f])
            p.push({dist[x.f] = x.s+a.f,x.f});
    }
}

void genEdge() {
    adj.resize(3*sz(p));
    F0R(i,sz(p)) {
        F0R(j,sz(p)) if (i != j) {
            auto a = dis(p[i],p[j]);
            // cout << p[i].f << " " << p[i].s << " " << p[j].f << " " << p[j].s << " " << a.f << " " << a.s << "\n";
            if (a.f == INF) continue;
            F0R(k,3) if (0 <= k+a.s && k+a.s < 3) 
                adj[i+k*sz(p)].pb({j+(k+a.s)*sz(p),a.f});
        }
    }
}

int main() {
    input();
    genEdge();
    // exit(0);
    F0R(i,2*sz(p)) {
        genDist(i);
        ans = min(ans,dist[i+sz(p)]);
    }
    cout << fixed << setprecision(9) << ans;
}

/* Look for:
* the exact constraints (multiple sets are too slow for n=10^6 :( ) 
* special cases (n=1?)
* overflow (ll vs int?)
* array bounds
*/

Compilation message

fences.cpp: In function 'void input()':
fences.cpp:120:23: warning: narrowing conversion of 'S' from 'int' to 'long double' inside { } [-Wnarrowing]
     p.pb({{S,S},{S,S}});
                       ^
fences.cpp:120:23: warning: narrowing conversion of 'S' from 'int' to 'long double' inside { } [-Wnarrowing]
fences.cpp:120:23: warning: narrowing conversion of 'S' from 'int' to 'long double' inside { } [-Wnarrowing]
fences.cpp:120:23: warning: narrowing conversion of 'S' from 'int' to 'long double' inside { } [-Wnarrowing]
fences.cpp:121:25: warning: narrowing conversion of 'S' from 'int' to 'long double' inside { } [-Wnarrowing]
     p.pb({{S,-S},{S,-S}});
                         ^
fences.cpp:121:14: warning: narrowing conversion of '- S' from 'int' to 'long double' inside { } [-Wnarrowing]
     p.pb({{S,-S},{S,-S}});
              ^~
fences.cpp:121:25: warning: narrowing conversion of 'S' from 'int' to 'long double' inside { } [-Wnarrowing]
     p.pb({{S,-S},{S,-S}});
                         ^
fences.cpp:121:21: warning: narrowing conversion of '- S' from 'int' to 'long double' inside { } [-Wnarrowing]
     p.pb({{S,-S},{S,-S}});
                     ^~
fences.cpp:122:12: warning: narrowing conversion of '- S' from 'int' to 'long double' inside { } [-Wnarrowing]
     p.pb({{-S,S},{-S,S}});
            ^~
fences.cpp:122:25: warning: narrowing conversion of 'S' from 'int' to 'long double' inside { } [-Wnarrowing]
     p.pb({{-S,S},{-S,S}});
                         ^
fences.cpp:122:19: warning: narrowing conversion of '- S' from 'int' to 'long double' inside { } [-Wnarrowing]
     p.pb({{-S,S},{-S,S}});
                   ^~
fences.cpp:122:25: warning: narrowing conversion of 'S' from 'int' to 'long double' inside { } [-Wnarrowing]
     p.pb({{-S,S},{-S,S}});
                         ^
fences.cpp:123:12: warning: narrowing conversion of '- S' from 'int' to 'long double' inside { } [-Wnarrowing]
     p.pb({{-S,-S},{-S,-S}});
            ^~
fences.cpp:123:15: warning: narrowing conversion of '- S' from 'int' to 'long double' inside { } [-Wnarrowing]
     p.pb({{-S,-S},{-S,-S}});
               ^~
fences.cpp:123:20: warning: narrowing conversion of '- S' from 'int' to 'long double' inside { } [-Wnarrowing]
     p.pb({{-S,-S},{-S,-S}});
                    ^~
fences.cpp:123:23: warning: narrowing conversion of '- S' from 'int' to 'long double' inside { } [-Wnarrowing]
     p.pb({{-S,-S},{-S,-S}});
                       ^~

Subtask #1
18.0 / 18.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 248 KB Output is correct
2 Correct 3 ms 484 KB Output is correct
3 Correct 2 ms 536 KB Output is correct
4 Correct 3 ms 536 KB Output is correct
5 Correct 2 ms 584 KB Output is correct
6 Correct 3 ms 584 KB Output is correct
7 Correct 2 ms 588 KB Output is correct
8 Correct 2 ms 588 KB Output is correct
9 Correct 2 ms 588 KB Output is correct
10 Correct 3 ms 588 KB Output is correct
11 Correct 3 ms 588 KB Output is correct
12 Correct 2 ms 588 KB Output is correct
13 Correct 3 ms 588 KB Output is correct
14 Correct 2 ms 588 KB Output is correct
15 Correct 3 ms 588 KB Output is correct
16 Correct 2 ms 588 KB Output is correct
17 Correct 3 ms 588 KB Output is correct
18 Correct 3 ms 652 KB Output is correct
19 Correct 2 ms 656 KB Output is correct
20 Correct 2 ms 656 KB Output is correct

Subtask #2
33.0 / 33.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 248 KB Output is correct
2 Correct 3 ms 484 KB Output is correct
3 Correct 2 ms 536 KB Output is correct
4 Correct 3 ms 536 KB Output is correct
5 Correct 2 ms 584 KB Output is correct
6 Correct 3 ms 584 KB Output is correct
7 Correct 2 ms 588 KB Output is correct
8 Correct 2 ms 588 KB Output is correct
9 Correct 2 ms 588 KB Output is correct
10 Correct 3 ms 588 KB Output is correct
11 Correct 3 ms 588 KB Output is correct
12 Correct 2 ms 588 KB Output is correct
13 Correct 3 ms 588 KB Output is correct
14 Correct 2 ms 588 KB Output is correct
15 Correct 3 ms 588 KB Output is correct
16 Correct 2 ms 588 KB Output is correct
17 Correct 3 ms 588 KB Output is correct
18 Correct 3 ms 652 KB Output is correct
19 Correct 2 ms 656 KB Output is correct
20 Correct 2 ms 656 KB Output is correct
21 Correct 3 ms 656 KB Output is correct
22 Correct 2 ms 656 KB Output is correct
23 Correct 3 ms 656 KB Output is correct
24 Correct 4 ms 656 KB Output is correct
25 Correct 3 ms 656 KB Output is correct
26 Correct 3 ms 656 KB Output is correct
27 Correct 3 ms 656 KB Output is correct
28 Correct 3 ms 656 KB Output is correct
29 Correct 3 ms 656 KB Output is correct
30 Correct 4 ms 656 KB Output is correct
31 Correct 3 ms 656 KB Output is correct
32 Correct 3 ms 656 KB Output is correct
33 Correct 4 ms 656 KB Output is correct
34 Correct 3 ms 656 KB Output is correct
35 Correct 3 ms 656 KB Output is correct
36 Correct 3 ms 656 KB Output is correct
37 Correct 2 ms 656 KB Output is correct
38 Correct 2 ms 656 KB Output is correct
39 Correct 3 ms 656 KB Output is correct
40 Correct 2 ms 708 KB Output is correct
41 Correct 3 ms 708 KB Output is correct
42 Correct 3 ms 708 KB Output is correct
43 Correct 3 ms 708 KB Output is correct

Subtask #3
0 / 49.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 248 KB Output is correct
2 Correct 3 ms 484 KB Output is correct
3 Correct 2 ms 536 KB Output is correct
4 Correct 3 ms 536 KB Output is correct
5 Correct 2 ms 584 KB Output is correct
6 Correct 3 ms 584 KB Output is correct
7 Correct 2 ms 588 KB Output is correct
8 Correct 2 ms 588 KB Output is correct
9 Correct 2 ms 588 KB Output is correct
10 Correct 3 ms 588 KB Output is correct
11 Correct 3 ms 588 KB Output is correct
12 Correct 2 ms 588 KB Output is correct
13 Correct 3 ms 588 KB Output is correct
14 Correct 2 ms 588 KB Output is correct
15 Correct 3 ms 588 KB Output is correct
16 Correct 2 ms 588 KB Output is correct
17 Correct 3 ms 588 KB Output is correct
18 Correct 3 ms 652 KB Output is correct
19 Correct 2 ms 656 KB Output is correct
20 Correct 2 ms 656 KB Output is correct
21 Correct 3 ms 656 KB Output is correct
22 Correct 2 ms 656 KB Output is correct
23 Correct 3 ms 656 KB Output is correct
24 Correct 4 ms 656 KB Output is correct
25 Correct 3 ms 656 KB Output is correct
26 Correct 3 ms 656 KB Output is correct
27 Correct 3 ms 656 KB Output is correct
28 Correct 3 ms 656 KB Output is correct
29 Correct 3 ms 656 KB Output is correct
30 Correct 4 ms 656 KB Output is correct
31 Correct 3 ms 656 KB Output is correct
32 Correct 3 ms 656 KB Output is correct
33 Correct 4 ms 656 KB Output is correct
34 Correct 3 ms 656 KB Output is correct
35 Correct 3 ms 656 KB Output is correct
36 Correct 3 ms 656 KB Output is correct
37 Correct 2 ms 656 KB Output is correct
38 Correct 2 ms 656 KB Output is correct
39 Correct 3 ms 656 KB Output is correct
40 Correct 2 ms 708 KB Output is correct
41 Correct 3 ms 708 KB Output is correct
42 Correct 3 ms 708 KB Output is correct
43 Correct 3 ms 708 KB Output is correct
44 Correct 184 ms 2156 KB Output is correct
45 Correct 195 ms 2156 KB Output is correct
46 Correct 172 ms 2156 KB Output is correct
47 Correct 148 ms 2156 KB Output is correct
48 Correct 175 ms 2156 KB Output is correct
49 Correct 227 ms 2300 KB Output is correct
50 Correct 172 ms 2300 KB Output is correct
51 Correct 174 ms 2300 KB Output is correct
52 Correct 188 ms 2300 KB Output is correct
53 Correct 161 ms 2300 KB Output is correct
54 Correct 181 ms 2300 KB Output is correct
55 Correct 312 ms 2300 KB Output is correct
56 Correct 223 ms 2300 KB Output is correct
57 Correct 194 ms 2300 KB Output is correct
58 Correct 174 ms 2300 KB Output is correct
59 Correct 182 ms 2300 KB Output is correct
60 Correct 239 ms 2300 KB Output is correct
61 Correct 242 ms 2300 KB Output is correct
62 Correct 4 ms 2300 KB Output is correct
63 Correct 3 ms 2300 KB Output is correct
64 Correct 336 ms 2300 KB Output is correct
65 Correct 547 ms 2300 KB Output is correct
66 Correct 373 ms 2300 KB Output is correct
67 Incorrect 416 ms 2396 KB Output isn't correct
68 Halted 0 ms 0 KB -