Submission #995530

#	Time	Username	Problem	Language	Result	Execution time	Memory
995530		vladilius	Road Construction (JOI21_road_construction)	C++17	100 / 100	1628 ms	26224 KiB

road_construction

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<ll, ll>;
#define pb push_back
#define ff first
#define ss second
#define ins insert
const ll inf = 1e9;

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    
    int n, k; cin>>n>>k;
    vector<pii> p(n + 1);
    for (int i = 1; i <= n; i++){
        cin>>p[i].ff>>p[i].ss;
    }
    sort(p.begin() + 1, p.end());
    vector<ll> dist;
    auto get = [&](ll r, bool ind){
        multiset<pii> st;
        int j = 1;
        for (int i = 1; i <= n; i++){
            if (ind && dist.size() >= k) break;
            while (j < i && (p[i].ff - p[j].ff) > r){
                st.erase(st.find({p[j].ss, p[j].ff}));
                j++;
            }
            auto it = st.lower_bound({p[i].ss - r, -inf});
            ll R = p[i].ss + r;
            while (it != st.end() && (*it).ff <= R){
                ll d = abs(p[i].ff - (*it).ss) + abs(p[i].ss - (*it).ff);
                if (d <= r){
                    dist.pb(d);
                }
                it++;
            }
            st.insert({p[i].ss, p[i].ff});
        }
    };
    
    ll l = 0, r = 4LL * inf;
    while (l + 1 < r){
        ll m = (l + r) / 2;
        get(m, 1);
        if (dist.size() < k){
            l = m + 1;
        }
        else {
            r = m;
        }
        dist.clear();
    }
    get(r, 0);
    assert(dist.size() >= k);
    sort(dist.begin(), dist.end());
    for (int i = 0; i < k; i++){
        cout<<dist[i]<<"\n";
    }
}

Compilation message (stderr)

road_construction.cpp: In lambda function:
road_construction.cpp:27:36: warning: comparison of integer expressions of different signedness: 'std::vector<long long int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   27 |             if (ind && dist.size() >= k) break;
      |                        ~~~~~~~~~~~~^~~~
road_construction.cpp: In function 'int main()':
road_construction.cpp:49:25: warning: comparison of integer expressions of different signedness: 'std::vector<long long int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   49 |         if (dist.size() < k){
      |             ~~~~~~~~~~~~^~~
In file included from /usr/include/c++/10/cassert:44,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:33,
                 from road_construction.cpp:1:
road_construction.cpp:58:24: warning: comparison of integer expressions of different signedness: 'std::vector<long long int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   58 |     assert(dist.size() >= k);
      |            ~~~~~~~~~~~~^~~~

• Subtask 1: 5 / 5
• Subtask 2: 6 / 6
• Subtask 3: 7 / 7
• Subtask 4: 20 / 20
• Subtask 5: 27 / 27
• Subtask 6: 35 / 35