Submission #62329

# Submission time Handle Problem Language Result Execution time Memory
62329 2018-07-28T05:47:07 Z Benq Fences (JOI18_fences) C++11
51 / 100
434 ms 17444 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});
    }
}
 
ld dist[300][101];

void genDist(int x) {
    F0R(i,sz(p)) F0R(j,101) dist[i][j] = INF;
    priority_queue<pair<ld,pi>,vector<pair<ld,pi>>,greater<pair<ld,pi>>> p;
    p.push({dist[x][50] = 0, {x,0}});
    while (sz(p)) {
        auto a = p.top(); p.pop();
        if (a.f > dist[a.s.f][a.s.s+50]) 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 (x.s.f+a.f < dist[t.f][t.s+50]) {
                p.push({dist[t.f][t.s+50] = 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:117:23: warning: narrowing conversion of 'S' from 'int' to 'long double' inside { } [-Wnarrowing]
     p.pb({{S,S},{S,S}});
                       ^
fences.cpp:117:23: warning: narrowing conversion of 'S' from 'int' to 'long double' inside { } [-Wnarrowing]
fences.cpp:117:23: warning: narrowing conversion of 'S' from 'int' to 'long double' inside { } [-Wnarrowing]
fences.cpp:117:23: warning: narrowing conversion of 'S' from 'int' to 'long double' inside { } [-Wnarrowing]
fences.cpp:118:25: warning: narrowing conversion of 'S' from 'int' to 'long double' inside { } [-Wnarrowing]
     p.pb({{S,-S},{S,-S}});
                         ^
fences.cpp:118:14: warning: narrowing conversion of '- S' from 'int' to 'long double' inside { } [-Wnarrowing]
     p.pb({{S,-S},{S,-S}});
              ^~
fences.cpp:118:25: warning: narrowing conversion of 'S' from 'int' to 'long double' inside { } [-Wnarrowing]
     p.pb({{S,-S},{S,-S}});
                         ^
fences.cpp:118:21: warning: narrowing conversion of '- S' from 'int' to 'long double' inside { } [-Wnarrowing]
     p.pb({{S,-S},{S,-S}});
                     ^~
fences.cpp:119:12: 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:119:19: 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:120:12: warning: narrowing conversion of '- S' from 'int' to 'long double' inside { } [-Wnarrowing]
     p.pb({{-S,-S},{-S,-S}});
            ^~
fences.cpp:120:15: warning: narrowing conversion of '- S' from 'int' to 'long double' inside { } [-Wnarrowing]
     p.pb({{-S,-S},{-S,-S}});
               ^~
fences.cpp:120:20: 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]
     p.pb({{-S,-S},{-S,-S}});
                       ^~
# Verdict Execution time Memory Grader output
1 Correct 2 ms 248 KB Output is correct
2 Correct 2 ms 356 KB Output is correct
3 Correct 3 ms 432 KB Output is correct
4 Correct 3 ms 432 KB Output is correct
5 Correct 3 ms 468 KB Output is correct
6 Correct 3 ms 468 KB Output is correct
7 Correct 2 ms 516 KB Output is correct
8 Correct 4 ms 516 KB Output is correct
9 Correct 4 ms 520 KB Output is correct
10 Correct 3 ms 624 KB Output is correct
11 Correct 3 ms 624 KB Output is correct
12 Correct 4 ms 624 KB Output is correct
13 Correct 3 ms 624 KB Output is correct
14 Correct 2 ms 624 KB Output is correct
15 Correct 3 ms 624 KB Output is correct
16 Correct 3 ms 624 KB Output is correct
17 Correct 3 ms 624 KB Output is correct
18 Correct 3 ms 624 KB Output is correct
19 Correct 3 ms 624 KB Output is correct
20 Correct 3 ms 744 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 2 ms 248 KB Output is correct
2 Correct 2 ms 356 KB Output is correct
3 Correct 3 ms 432 KB Output is correct
4 Correct 3 ms 432 KB Output is correct
5 Correct 3 ms 468 KB Output is correct
6 Correct 3 ms 468 KB Output is correct
7 Correct 2 ms 516 KB Output is correct
8 Correct 4 ms 516 KB Output is correct
9 Correct 4 ms 520 KB Output is correct
10 Correct 3 ms 624 KB Output is correct
11 Correct 3 ms 624 KB Output is correct
12 Correct 4 ms 624 KB Output is correct
13 Correct 3 ms 624 KB Output is correct
14 Correct 2 ms 624 KB Output is correct
15 Correct 3 ms 624 KB Output is correct
16 Correct 3 ms 624 KB Output is correct
17 Correct 3 ms 624 KB Output is correct
18 Correct 3 ms 624 KB Output is correct
19 Correct 3 ms 624 KB Output is correct
20 Correct 3 ms 744 KB Output is correct
21 Correct 3 ms 744 KB Output is correct
22 Correct 3 ms 744 KB Output is correct
23 Correct 3 ms 744 KB Output is correct
24 Correct 4 ms 744 KB Output is correct
25 Correct 3 ms 744 KB Output is correct
26 Correct 3 ms 744 KB Output is correct
27 Correct 2 ms 744 KB Output is correct
28 Correct 4 ms 744 KB Output is correct
29 Correct 3 ms 744 KB Output is correct
30 Correct 4 ms 744 KB Output is correct
31 Correct 3 ms 744 KB Output is correct
32 Correct 4 ms 744 KB Output is correct
33 Correct 3 ms 744 KB Output is correct
34 Correct 3 ms 744 KB Output is correct
35 Correct 4 ms 744 KB Output is correct
36 Correct 3 ms 744 KB Output is correct
37 Correct 3 ms 744 KB Output is correct
38 Correct 4 ms 744 KB Output is correct
39 Correct 3 ms 744 KB Output is correct
40 Correct 2 ms 744 KB Output is correct
41 Correct 3 ms 744 KB Output is correct
42 Correct 4 ms 744 KB Output is correct
43 Correct 5 ms 748 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 2 ms 248 KB Output is correct
2 Correct 2 ms 356 KB Output is correct
3 Correct 3 ms 432 KB Output is correct
4 Correct 3 ms 432 KB Output is correct
5 Correct 3 ms 468 KB Output is correct
6 Correct 3 ms 468 KB Output is correct
7 Correct 2 ms 516 KB Output is correct
8 Correct 4 ms 516 KB Output is correct
9 Correct 4 ms 520 KB Output is correct
10 Correct 3 ms 624 KB Output is correct
11 Correct 3 ms 624 KB Output is correct
12 Correct 4 ms 624 KB Output is correct
13 Correct 3 ms 624 KB Output is correct
14 Correct 2 ms 624 KB Output is correct
15 Correct 3 ms 624 KB Output is correct
16 Correct 3 ms 624 KB Output is correct
17 Correct 3 ms 624 KB Output is correct
18 Correct 3 ms 624 KB Output is correct
19 Correct 3 ms 624 KB Output is correct
20 Correct 3 ms 744 KB Output is correct
21 Correct 3 ms 744 KB Output is correct
22 Correct 3 ms 744 KB Output is correct
23 Correct 3 ms 744 KB Output is correct
24 Correct 4 ms 744 KB Output is correct
25 Correct 3 ms 744 KB Output is correct
26 Correct 3 ms 744 KB Output is correct
27 Correct 2 ms 744 KB Output is correct
28 Correct 4 ms 744 KB Output is correct
29 Correct 3 ms 744 KB Output is correct
30 Correct 4 ms 744 KB Output is correct
31 Correct 3 ms 744 KB Output is correct
32 Correct 4 ms 744 KB Output is correct
33 Correct 3 ms 744 KB Output is correct
34 Correct 3 ms 744 KB Output is correct
35 Correct 4 ms 744 KB Output is correct
36 Correct 3 ms 744 KB Output is correct
37 Correct 3 ms 744 KB Output is correct
38 Correct 4 ms 744 KB Output is correct
39 Correct 3 ms 744 KB Output is correct
40 Correct 2 ms 744 KB Output is correct
41 Correct 3 ms 744 KB Output is correct
42 Correct 4 ms 744 KB Output is correct
43 Correct 5 ms 748 KB Output is correct
44 Correct 100 ms 1752 KB Output is correct
45 Correct 82 ms 1752 KB Output is correct
46 Correct 95 ms 1752 KB Output is correct
47 Correct 65 ms 1752 KB Output is correct
48 Correct 91 ms 1852 KB Output is correct
49 Correct 108 ms 1852 KB Output is correct
50 Correct 93 ms 1852 KB Output is correct
51 Correct 81 ms 1852 KB Output is correct
52 Correct 85 ms 1852 KB Output is correct
53 Correct 79 ms 1852 KB Output is correct
54 Correct 106 ms 1852 KB Output is correct
55 Correct 116 ms 1852 KB Output is correct
56 Correct 102 ms 1852 KB Output is correct
57 Correct 71 ms 1852 KB Output is correct
58 Correct 75 ms 1852 KB Output is correct
59 Correct 81 ms 1852 KB Output is correct
60 Correct 89 ms 1852 KB Output is correct
61 Correct 129 ms 1916 KB Output is correct
62 Correct 4 ms 1916 KB Output is correct
63 Correct 5 ms 1916 KB Output is correct
64 Correct 68 ms 1916 KB Output is correct
65 Correct 128 ms 1916 KB Output is correct
66 Correct 110 ms 1916 KB Output is correct
67 Correct 434 ms 17444 KB Output is correct
68 Correct 267 ms 17444 KB Output is correct
69 Incorrect 76 ms 17444 KB Output isn't correct
70 Halted 0 ms 0 KB -