Submission #882341

#	Time	Username	Problem	Language	Result	Execution time	Memory
882341		pirhosig	Finding Routers (IOI20_routers)	C++17	98.19 / 100	1 ms	600 KiB

routers

#include "routers.h"
#include <bits/stdc++.h>
using namespace std;



int solve(int low, int upp, int val) {
    while (low < upp) {
        int mid = (low + upp + 1) / 2;
        int qres = use_detector(mid);
        // cerr << mid << endl;
        if (qres >= val) upp = mid - 1;
        else low = mid;
    }
    return low;
}



vector<int> find_routers(int l, int n, int q) {
    vector<int> ans;
    ans.push_back(0);
    if (n == 2) {
        int res = solve(0, l, 1);
        ans.push_back(res * 2);
        return ans;
    }
    vector<pair<int, int>> close;
    close.push_back({0, 0});
    constexpr int jump = 160;
    for (int i = jump; i < l; i += jump) close.push_back({use_detector(i), i});
    close.push_back({use_detector(l), l});
    for (int i = 1; i < n; ++i) {
        auto upp = lower_bound(close.begin(), close.end(), make_pair(i, 0));
        auto low = prev(upp);
        int res = solve(low->second, upp->second, i);
        ans.push_back(2 * res - ans.back());
    }
    return ans;
}

• Subtask 1: 16 / 16
• Subtask 2: 21 / 21
• Subtask 3: 23 / 23
• Subtask 4: 38.1888 / 40