Submission #1116795

#	Time	Username	Problem	Language	Result	Execution time	Memory
1116795		vladilius	Finding Routers (IOI20_routers)	C++17	46.83 / 100	2 ms	604 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){
    auto f = [&](int x){
        return use_detector(x);
    };
    vector<pii> rr(n);
    function<void(int, int, int, int)> solve = [&](int l, int r, int l1, int r1){
        if (l > r) return;
        int m = (l + r) / 2;
        int lb = l1, rb = r1;
        while (lb + 1 < rb){
            int mb = (lb + rb) / 2, t = f(mb);
            if (t < m){
                lb = mb + 1;
            }
            else {
                rb = mb - (t != m);
            }
        }
        while (f(lb) != m) lb++;
        
        int L = lb;
        rb = r1;
        while (lb + 1 < rb){
            int mb = (lb + rb) / 2, t = f(mb);
            if (t > m){
                rb = mb - 1;
            }
            else {
                lb = mb;
            }
        }
        while (f(rb) != m) rb--;
        
        int R = rb;
        
        rr[m] = {L, R};
        
        solve(l, m - 1, l1, L - 1);
        solve(m + 1, r, R + 1, r1);

    };
    solve(0, n - 1, 0, k);
    
    vector<int> out = {0};
    for (int i = 0; i < n - 1; i++){
        out.pb(2 * rr[i].ss - out.back());
    };
    return out;
}

• Subtask 1: 16 / 16
• Subtask 2: 21 / 21
• Subtask 3: 0 / 23
• Subtask 4: 9.8336 / 40