oj.uz

Submission #62328

# Submission time Handle Problem Language Result Execution time Memory
62328 2018-07-28T05:42:11 Z Benq Fences (JOI18_fences) C++11
51 / 100
 1000 ms 17448 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-14;

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,pair<ld,int>>>> adj;
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});
    }
}

map<pi,ld> dist;

void genDist(int x) {
    dist.clear();
    priority_queue<pair<ld,pi>,vector<pair<ld,pi>>,greater<pair<ld,pi>>> p;
    p.push({dist[{x,0}] = 0, {x,0}});
    while (sz(p)) {
        auto a = p.top(); p.pop();
        if (a.f > dist[a.s]) continue;
        if (a.s.f == x && a.s.s != 0) {
            ans = min(ans,a.f);
            return;
        }
        for (auto x: adj[a.s.f]) {
            pi t = {x.f,a.s.s+x.s.s};
            if (abs(t.s) > 50) continue;
            if (!dist.count(t) || x.s.f+a.f < dist[t]) {
                p.push({dist[t] = x.s.f+a.f,t});
            }
        }
    }
}

void genEdge() {
    // for (auto a: p) cout << a.f << " " << a.s << "\n";
    adj.resize(sz(p));
    F0R(i,sz(p)) {
        F0R(j,sz(p)) if (i != j) {
            auto a = dis(p[i],p[j]);
            if (a.f == INF) continue;
            /*if (i < j && a.f <= (1e-9)) {
                cout << i << " " << j << "\n";
                cout << p[i].f << " " << p[i].s << " " << p[j].f << " " << p[j].s << " " << a.f << " " << a.s << "\n";
            }*/
            adj[i].pb({j,a});
        }
    }
}

int main() {
    input();
    genEdge();
    F0R(i,sz(p)) genDist(i);
    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:118:23: warning: narrowing conversion of 'S' from 'int' to 'long double' inside { } [-Wnarrowing]
     p.pb({{S,S},{S,S}});
                       ^
fences.cpp:118:23: warning: narrowing conversion of 'S' from 'int' to 'long double' inside { } [-Wnarrowing]
fences.cpp:118:23: warning: narrowing conversion of 'S' from 'int' to 'long double' inside { } [-Wnarrowing]
fences.cpp:118:23: warning: narrowing conversion of 'S' from 'int' to 'long double' inside { } [-Wnarrowing]
fences.cpp:119:25: warning: narrowing conversion of 'S' from 'int' to 'long double' inside { } [-Wnarrowing]
     p.pb({{S,-S},{S,-S}});
                         ^
fences.cpp:119:14: warning: narrowing conversion of '- S' from 'int' to 'long double' inside { } [-Wnarrowing]
     p.pb({{S,-S},{S,-S}});
              ^~
fences.cpp:119:25: warning: narrowing conversion of 'S' from 'int' to 'long double' inside { } [-Wnarrowing]
     p.pb({{S,-S},{S,-S}});
                         ^
fences.cpp:119:21: warning: narrowing conversion of '- S' from 'int' to 'long double' inside { } [-Wnarrowing]
     p.pb({{S,-S},{S,-S}});
                     ^~
fences.cpp:120:12: warning: narrowing conversion of '- S' from 'int' to 'long double' inside { } [-Wnarrowing]
     p.pb({{-S,S},{-S,S}});
            ^~
fences.cpp:120:25: warning: narrowing conversion of 'S' from 'int' to 'long double' inside { } [-Wnarrowing]
     p.pb({{-S,S},{-S,S}});
                         ^
fences.cpp:120:19: warning: narrowing conversion of '- S' from 'int' to 'long double' inside { } [-Wnarrowing]
     p.pb({{-S,S},{-S,S}});
                   ^~
fences.cpp:120:25: warning: narrowing conversion of 'S' from 'int' to 'long double' inside { } [-Wnarrowing]
     p.pb({{-S,S},{-S,S}});
                         ^
fences.cpp:121:12: warning: narrowing conversion of '- S' from 'int' to 'long double' inside { } [-Wnarrowing]
     p.pb({{-S,-S},{-S,-S}});
            ^~
fences.cpp:121:15: warning: narrowing conversion of '- S' from 'int' to 'long double' inside { } [-Wnarrowing]
     p.pb({{-S,-S},{-S,-S}});
               ^~
fences.cpp:121:20: warning: narrowing conversion of '- S' from 'int' to 'long double' inside { } [-Wnarrowing]
     p.pb({{-S,-S},{-S,-S}});
                    ^~
fences.cpp:121:23: warning: narrowing conversion of '- S' from 'int' to 'long double' inside { } [-Wnarrowing]
     p.pb({{-S,-S},{-S,-S}});
                       ^~

Subtask #1
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 376 KB Output is correct
2 Correct 3 ms 376 KB Output is correct
3 Correct 3 ms 564 KB Output is correct
4 Correct 3 ms 564 KB Output is correct
5 Correct 3 ms 668 KB Output is correct
6 Correct 2 ms 668 KB Output is correct
7 Correct 3 ms 668 KB Output is correct
8 Correct 2 ms 668 KB Output is correct
9 Correct 2 ms 668 KB Output is correct
10 Correct 2 ms 668 KB Output is correct
11 Correct 3 ms 668 KB Output is correct
12 Correct 3 ms 724 KB Output is correct
13 Correct 3 ms 724 KB Output is correct
14 Correct 3 ms 724 KB Output is correct
15 Correct 2 ms 724 KB Output is correct
16 Correct 3 ms 724 KB Output is correct
17 Correct 3 ms 724 KB Output is correct
18 Correct 2 ms 724 KB Output is correct
19 Correct 3 ms 724 KB Output is correct
20 Correct 3 ms 724 KB Output is correct

Subtask #2
33.0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 376 KB Output is correct
2 Correct 3 ms 376 KB Output is correct
3 Correct 3 ms 564 KB Output is correct
4 Correct 3 ms 564 KB Output is correct
5 Correct 3 ms 668 KB Output is correct
6 Correct 2 ms 668 KB Output is correct
7 Correct 3 ms 668 KB Output is correct
8 Correct 2 ms 668 KB Output is correct
9 Correct 2 ms 668 KB Output is correct
10 Correct 2 ms 668 KB Output is correct
11 Correct 3 ms 668 KB Output is correct
12 Correct 3 ms 724 KB Output is correct
13 Correct 3 ms 724 KB Output is correct
14 Correct 3 ms 724 KB Output is correct
15 Correct 2 ms 724 KB Output is correct
16 Correct 3 ms 724 KB Output is correct
17 Correct 3 ms 724 KB Output is correct
18 Correct 2 ms 724 KB Output is correct
19 Correct 3 ms 724 KB Output is correct
20 Correct 3 ms 724 KB Output is correct
21 Correct 2 ms 724 KB Output is correct
22 Correct 2 ms 724 KB Output is correct
23 Correct 3 ms 748 KB Output is correct
24 Correct 3 ms 748 KB Output is correct
25 Correct 2 ms 748 KB Output is correct
26 Correct 3 ms 748 KB Output is correct
27 Correct 3 ms 748 KB Output is correct
28 Correct 5 ms 748 KB Output is correct
29 Correct 3 ms 748 KB Output is correct
30 Correct 3 ms 748 KB Output is correct
31 Correct 3 ms 748 KB Output is correct
32 Correct 3 ms 748 KB Output is correct
33 Correct 3 ms 748 KB Output is correct
34 Correct 4 ms 748 KB Output is correct
35 Correct 4 ms 748 KB Output is correct
36 Correct 3 ms 748 KB Output is correct
37 Correct 3 ms 748 KB Output is correct
38 Correct 3 ms 748 KB Output is correct
39 Correct 4 ms 748 KB Output is correct
40 Correct 2 ms 748 KB Output is correct
41 Correct 3 ms 748 KB Output is correct
42 Correct 2 ms 748 KB Output is correct
43 Correct 9 ms 860 KB Output is correct

Subtask #3
0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 376 KB Output is correct
2 Correct 3 ms 376 KB Output is correct
3 Correct 3 ms 564 KB Output is correct
4 Correct 3 ms 564 KB Output is correct
5 Correct 3 ms 668 KB Output is correct
6 Correct 2 ms 668 KB Output is correct
7 Correct 3 ms 668 KB Output is correct
8 Correct 2 ms 668 KB Output is correct
9 Correct 2 ms 668 KB Output is correct
10 Correct 2 ms 668 KB Output is correct
11 Correct 3 ms 668 KB Output is correct
12 Correct 3 ms 724 KB Output is correct
13 Correct 3 ms 724 KB Output is correct
14 Correct 3 ms 724 KB Output is correct
15 Correct 2 ms 724 KB Output is correct
16 Correct 3 ms 724 KB Output is correct
17 Correct 3 ms 724 KB Output is correct
18 Correct 2 ms 724 KB Output is correct
19 Correct 3 ms 724 KB Output is correct
20 Correct 3 ms 724 KB Output is correct
21 Correct 2 ms 724 KB Output is correct
22 Correct 2 ms 724 KB Output is correct
23 Correct 3 ms 748 KB Output is correct
24 Correct 3 ms 748 KB Output is correct
25 Correct 2 ms 748 KB Output is correct
26 Correct 3 ms 748 KB Output is correct
27 Correct 3 ms 748 KB Output is correct
28 Correct 5 ms 748 KB Output is correct
29 Correct 3 ms 748 KB Output is correct
30 Correct 3 ms 748 KB Output is correct
31 Correct 3 ms 748 KB Output is correct
32 Correct 3 ms 748 KB Output is correct
33 Correct 3 ms 748 KB Output is correct
34 Correct 4 ms 748 KB Output is correct
35 Correct 4 ms 748 KB Output is correct
36 Correct 3 ms 748 KB Output is correct
37 Correct 3 ms 748 KB Output is correct
38 Correct 3 ms 748 KB Output is correct
39 Correct 4 ms 748 KB Output is correct
40 Correct 2 ms 748 KB Output is correct
41 Correct 3 ms 748 KB Output is correct
42 Correct 2 ms 748 KB Output is correct
43 Correct 9 ms 860 KB Output is correct
44 Correct 382 ms 1736 KB Output is correct
45 Correct 278 ms 1736 KB Output is correct
46 Correct 264 ms 1736 KB Output is correct
47 Correct 158 ms 1736 KB Output is correct
48 Correct 332 ms 1736 KB Output is correct
49 Correct 326 ms 1736 KB Output is correct
50 Correct 213 ms 1736 KB Output is correct
51 Correct 186 ms 1736 KB Output is correct
52 Correct 276 ms 1736 KB Output is correct
53 Correct 206 ms 1736 KB Output is correct
54 Correct 253 ms 1736 KB Output is correct
55 Correct 351 ms 1736 KB Output is correct
56 Correct 321 ms 1736 KB Output is correct
57 Correct 186 ms 1736 KB Output is correct
58 Correct 233 ms 1736 KB Output is correct
59 Correct 223 ms 1736 KB Output is correct
60 Correct 254 ms 1736 KB Output is correct
61 Correct 406 ms 1736 KB Output is correct
62 Correct 5 ms 1736 KB Output is correct
63 Correct 4 ms 1736 KB Output is correct
64 Correct 187 ms 1736 KB Output is correct
65 Correct 277 ms 1736 KB Output is correct
66 Correct 214 ms 1736 KB Output is correct
67 Execution timed out 1025 ms 17448 KB Time limit exceeded
68 Halted 0 ms 0 KB -