Submission #1058757

# Submission time Handle Problem Language Result Execution time Memory
1058757 2024-08-14T13:21:12 Z LittleOrange Fountain Parks (IOI21_parks) C++17
5 / 100
185 ms 52924 KB
#include "parks.h"
#include<bits/stdc++.h>
using namespace std;
using ll = int;
struct dsu{
    ll n;
    vector<ll> p;
    dsu(ll N):n(N),p(N,-1){}
    ll g(ll i){
        return p[i]<0?i:p[i]=g(p[i]);
    }
    bool m(ll a, ll b){
        a = g(a);
        b = g(b);
        if(a==b) return false;
        if(p[a]>p[b]) swap(a,b);
        p[a]+=p[b];
        p[b]=a;
        return true;
    }
};
struct obj{
    ll x,y,i;
    bool operator<(const obj &o) const{
        return x!=o.x?x<o.x:y<o.y;
    }
    obj operator+(const obj &o) const{
        return {x+o.x,y+o.y,i};
    }
    obj operator-(const obj &o) const{
        return {x-o.x,y-o.y,i};
    }
    bool operator==(const obj &o) const{
        return x==o.x&&y==o.y;
    }
    bool operator!=(const obj &o) const{
        return x!=o.x||y!=o.y;
    }
    obj turn() const{
        return {y,-x,i};
    }
};
using pos = obj;
ostream& operator<<(ostream& o, const pos &p){
    return o << "(" << p.x << "," << p.y << ";" << p.i << ")";
}
pos mid(const pos &a, const pos &b){
    return {(a.x+b.x)/2,(a.y+b.y)/2,0};
}
array<pos,2> mids(const pos &a, const pos &b){
    pos m = mid(a,b);
    array<pos,2> r = {m+(a-m).turn(),m+(b-m).turn()};
    //cerr << "mids of " << a << " " << b << " -> " << r[0] << " " << r[1] << "\n";
    return r;
}
int construct_roads(std::vector<int> x, std::vector<int> y) {
    ll n = x.size();
    vector<obj> fs = {{0,2,0},{0,-2,0},{2,0,0},{-2,0,0}};
    if (x.size() == 1) {
	    build({}, {}, {}, {});
        return 1;
    }
    vector<ll> ans_u,ans_v,ans_a,ans_b;
    vector<obj> a(n);
    for(ll i = 0;i<n;i++){
        a[i] = {x[i],y[i],i};
    }
    sort(a.begin(),a.end());
    dsu d(n);
    vector<pair<pos,pos>> cons;
    for(pos u : a){
        for(pos f : fs){
            pos v = u+f;
            auto it = lower_bound(a.begin(),a.end(),v);
            if (it==a.end()||*it!=v) continue;
            v = *it;
            if(d.m(u.i,v.i)){
                cons.push_back({u,v});
            }
        }
    }
    if(cons.size()<n-1)return 0;
    vector<pos> v;
    for(auto [p0,p1] : cons){
        for(pos p : mids(p0,p1)) v.push_back(p);
    }
    sort(v.begin(),v.end());
    v.erase(unique(v.begin(),v.end()),v.end());
    ll m = v.size();
    vector<pair<pos,pos>> ops;
    vector<vector<ll>> con(m);
    vector<ll> u(n-1,0);
    for(auto [p0,p1] : cons){
        auto o = mids(p0,p1);
        ll i = lower_bound(v.begin(),v.end(),o[0])-v.begin();
        ll j = lower_bound(v.begin(),v.end(),o[1])-v.begin();
        pair<pos,pos> op = {min(o[0],o[1]),max(o[0],o[1])};
        ops.push_back(op);
        con[i].push_back(j);
        con[j].push_back(i);
    }
    vector<ll> idl(m);
    iota(idl.begin(),idl.end(),0);
    sort(idl.begin(),idl.end(),[&](ll i, ll j){return con[i].size()<con[j].size();});
    for(ll i : idl){
        for(ll j : con[i]){
            pair<pos,pos> op = {min(v[i],v[j]),max(v[i],v[j])};
            auto it = lower_bound(ops.begin(),ops.end(),op);
            if (it==ops.end()) continue;
            if (*it!=op) continue;
            ll idx = it-ops.begin();
            if(u[idx]) continue;
            u[idx] = 1;
            pos p = v[i];
            ans_a.push_back(p.x);
            ans_b.push_back(p.y);
            auto os = mids(v[i],v[j]);
            //cerr << "use " << p << " from " << os[0] << " " << os[1] << "\n";
            ll idx1 = (*lower_bound(a.begin(),a.end(),os[0])).i;
            ll idx2 = (*lower_bound(a.begin(),a.end(),os[1])).i;
            ans_u.push_back(idx1);
            ans_v.push_back(idx2);
            break;
        }
    }
    if(ans_u.size()<n-1) return 0;
    build(ans_u,ans_v,ans_a,ans_b);
    return 1;
}

Compilation message

parks.cpp: In function 'int construct_roads(std::vector<int>, std::vector<int>)':
parks.cpp:82:19: warning: comparison of integer expressions of different signedness: 'std::vector<std::pair<obj, obj> >::size_type' {aka 'long unsigned int'} and 'll' {aka 'int'} [-Wsign-compare]
   82 |     if(cons.size()<n-1)return 0;
      |        ~~~~~~~~~~~^~~~
parks.cpp:126:20: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'll' {aka 'int'} [-Wsign-compare]
  126 |     if(ans_u.size()<n-1) return 0;
      |        ~~~~~~~~~~~~^~~~
# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 388 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 112 ms 28384 KB Output is correct
10 Correct 8 ms 3164 KB Output is correct
11 Correct 72 ms 14928 KB Output is correct
12 Correct 19 ms 4444 KB Output is correct
13 Correct 10 ms 3512 KB Output is correct
14 Correct 1 ms 344 KB Output is correct
15 Correct 1 ms 344 KB Output is correct
16 Correct 91 ms 27744 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 388 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 112 ms 28384 KB Output is correct
10 Correct 8 ms 3164 KB Output is correct
11 Correct 72 ms 14928 KB Output is correct
12 Correct 19 ms 4444 KB Output is correct
13 Correct 10 ms 3512 KB Output is correct
14 Correct 1 ms 344 KB Output is correct
15 Correct 1 ms 344 KB Output is correct
16 Correct 91 ms 27744 KB Output is correct
17 Correct 0 ms 348 KB Output is correct
18 Correct 0 ms 348 KB Output is correct
19 Incorrect 0 ms 348 KB Solution announced impossible, but it is possible.
20 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 388 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 112 ms 28384 KB Output is correct
10 Correct 8 ms 3164 KB Output is correct
11 Correct 72 ms 14928 KB Output is correct
12 Correct 19 ms 4444 KB Output is correct
13 Correct 10 ms 3512 KB Output is correct
14 Correct 1 ms 344 KB Output is correct
15 Correct 1 ms 344 KB Output is correct
16 Correct 91 ms 27744 KB Output is correct
17 Correct 0 ms 348 KB Output is correct
18 Correct 0 ms 348 KB Output is correct
19 Incorrect 0 ms 348 KB Solution announced impossible, but it is possible.
20 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 388 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 112 ms 28384 KB Output is correct
10 Correct 8 ms 3164 KB Output is correct
11 Correct 72 ms 14928 KB Output is correct
12 Correct 19 ms 4444 KB Output is correct
13 Correct 10 ms 3512 KB Output is correct
14 Correct 1 ms 344 KB Output is correct
15 Correct 1 ms 344 KB Output is correct
16 Correct 91 ms 27744 KB Output is correct
17 Correct 0 ms 348 KB Output is correct
18 Correct 0 ms 348 KB Output is correct
19 Correct 0 ms 348 KB Output is correct
20 Correct 185 ms 43496 KB Output is correct
21 Incorrect 138 ms 36152 KB Solution announced impossible, but it is possible.
22 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 388 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 112 ms 28384 KB Output is correct
10 Correct 8 ms 3164 KB Output is correct
11 Correct 72 ms 14928 KB Output is correct
12 Correct 19 ms 4444 KB Output is correct
13 Correct 10 ms 3512 KB Output is correct
14 Correct 1 ms 344 KB Output is correct
15 Correct 1 ms 344 KB Output is correct
16 Correct 91 ms 27744 KB Output is correct
17 Incorrect 154 ms 52924 KB Solution announced impossible, but it is possible.
18 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 388 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 112 ms 28384 KB Output is correct
10 Correct 8 ms 3164 KB Output is correct
11 Correct 72 ms 14928 KB Output is correct
12 Correct 19 ms 4444 KB Output is correct
13 Correct 10 ms 3512 KB Output is correct
14 Correct 1 ms 344 KB Output is correct
15 Correct 1 ms 344 KB Output is correct
16 Correct 91 ms 27744 KB Output is correct
17 Correct 0 ms 348 KB Output is correct
18 Correct 0 ms 348 KB Output is correct
19 Incorrect 0 ms 348 KB Solution announced impossible, but it is possible.
20 Halted 0 ms 0 KB -