Submission #893446

#	Time	Username	Problem	Language	Result	Execution time	Memory
893446		vjudge1	Road Construction (JOI21_road_construction)	C++17	100 / 100	7140 ms	705476 KiB

road_construction

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

#define int long long
#define pb push_back
#define ff first
#define ss second
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define ordered_set tree<ll, null_type, less<ll>, rb_tree_tag, tree_order_statistics_node_update>
#define ordered_multiset tree<int, null_type, less_equal<int>, rb_tree_tag, tree_order_statistics_node_update>

using namespace std;
using namespace __gnu_pbds;

const int mod = 998244353;
const double PI = acos(-1.0);
const double epsilon = 1e-6;
const int N = 2e5 + 5;

vector<pair<int, int>> a;
multiset<int> ans;
map<pair<pair<int,int>,pair<int,int> >,bool> vis;
int mindist = 1e18;
int n, k;

int dist(pair<int, int> f, pair<int, int> s){
    return abs(f.ff - s.ff) + abs(f.ss - s.ss);
}

void update(pair<int, int> f, pair<int, int> s){
	if(vis[{f,s}] || vis[{s,f}]) return;
    ans.insert(dist(f, s));
    vis[{f,s}] = 1;
    if ((int)ans.size() == k) mindist = *prev(ans.end());
    else if ((int)ans.size() > k) {
        ans.erase(prev(ans.end()));
        mindist = *prev(ans.end());
    }
}

bool cmp(pair<int, int> f, pair<int, int> s){
    return f.ss < s.ss;
}

void rec(int l, int r){
    if (r - l <= 3) {
        for (int i = l; i < r; i++) {
            for (int j = i + 1; j <= r; j++) {
                update(a[i], a[j]);
            }
        }
        sort(a.begin() + l, a.begin() + r + 1, cmp);
        return;
    }

    int m = (l + r) >> 1;
    int midx = a[m].ff;
    rec(l, m), rec(m + 1, r);
    vector<pair<int, int>> t(r - l + 1);
    merge(a.begin() + l, a.begin() + m + 1, a.begin() + m + 1, a.begin() + r + 1, t.begin(), cmp);
    copy(t.begin(), t.begin() + r - l + 1, a.begin() + l);

    int sz = 0;
    for (int i = l; i <= r; i++) {
        if (abs(a[i].ff - midx) < mindist) {
            for (int j = sz - 1; j >= 0 && a[i].ss - t[j].ss < mindist; j--) {
                update(a[i], t[j]);
            }
            t[sz++] = a[i];
        }
    }
}

void solve(){
    cin >> n >> k;
    for (int i = 0; i < n; i++) {
        int x, y;
        cin >> x >> y;
        a.pb({x, y});
    }
    sort(all(a));
    rec(0, n - 1);
    for (int i : ans) cout << i << '\n';
}

main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    int tt = 1;
    //cin >> tt;
    while (tt--) {
        solve();
    }
}

Compilation message (stderr)

road_construction.cpp:88:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   88 | main(){
      | ^~~~

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