Submission #1116886

#	Time	Username	Problem	Language	Result	Execution time	Memory
1116886		vladilius	Finding Routers (IOI20_routers)	C++17	99.09 / 100	5 ms	860 KiB

routers

#include <bits/stdc++.h>
#include "routers.h"
using namespace std;
using ll = long long;
using pii = pair<int, int>;
#define pb push_back
#define ff first
#define ss second

vector<int> find_routers(int k, int n, int q){
    map<int, int> mp;
    auto f = [&](int x){
        auto it = mp.find(x);
        if (it != mp.end()){
            return (*it).ss;
        }
        
        auto it1 = mp.lower_bound(x);
        if (it1 != mp.end() && it1 != mp.begin() && (*it1).ss == (*prev(it1)).ss){
            mp[x] = (*it1).ss;
        }
        else {
            mp[x] = use_detector(x);
        }
        
        return mp[x];
    };
    
    vector<int> rr(n);
    mt19937 rng((int) time(0));
    function<void(int, int, int, int)> solve = [&](int l, int r, int l1, int r1){
        if (l > r) return;
        int m = (l == r) ? l: (l + rng() % (r - l));
        
        int lb = l1, rb = r1;
        while (lb + 1 < rb){
            int mb = (lb + rb) / 2, t = f(mb);
            if (t > m){
                rb = mb;
            }
            else {
                lb = mb;
            }
        }
        if (lb != rb) while (f(rb) != m) rb--;
        rr[m] = rb;
        
        solve(l, m - 1, l1, rr[m]);
        solve(m + 1, r, rr[m], r1);
    };
    
    solve(0, n - 2, 0, k);
    
    vector<int> out = {0};
    for (int i = 0; i < n - 1; i++){
        out.pb(2 * rr[i] - out.back());
    };
    return out;
}

• Subtask 1: 16 / 16
• Subtask 2: 21 / 21
• Subtask 3: 23 / 23
• Subtask 4: 39.088 / 40