Submission #857350

#	Time	Username	Problem	Language	Result	Execution time	Memory
857350		resting	Overtaking (IOI23_overtaking)	C++17	0 / 100	1 ms	600 KiB

overtaking

#include "overtaking.h"
#include <bits/stdc++.h>

using namespace std;
#define int long long

vector<pair<int, int>> restriction; // if "starts after a", has to "end after b" yk

int x, l;
void init(int32_t L, int32_t N, std::vector<long long> T, std::vector<int32_t> W, int32_t X, int32_t M, std::vector<int32_t> S)
{
    x = X; l = L;
    vector<vector<pair<int, int>>> restrictions(M);// yes
    vector<pair<int, int>> cur;
    for (int i = 0; i < N; i++) if (W[i] > X) cur.push_back({ T[i], W[i] - X });
    sort(cur.begin(), cur.end());
    for (int i = 0; i < M; i++) {
        vector<pair<int, int>> res;
        for (int j = 0; j < N; j++) res.push_back({ cur[j].first + cur[j].second * (T[i + 1] - T[i]), cur[j].second });
        for (int j = 0; j < N - 1; j++) if (res[j].first > res[j + 1].first) res[j + 1].first = res[j].first;
        for (int j = 0; j < N; j++) restrictions[i].push_back({ cur[j].first, res[j].first }); //start, end
        swap(res, cur);
        sort(cur.begin(), cur.end());
    }
    //restrictions i guess ["start after i has to end after j"]
    restriction = restrictions[0];
    for (int i = 1; i < M; i++) {
        //transition from prev ???
        //two pointers
        vector<pair<int, int>> nice;
        auto l1 = restriction, l2 = restrictions[i];
        int p1 = restriction.size() - 1;
        int p2 = restrictions[i].size() - 1;
        int cur = 100000;
        while (p1 >= 0 && p2 >= 0) {
            if (p1 < 0) {
                nice.push_back(l2[p2]);
                cur = l2[p2].first;
                p2--;
            } else if (p2 < 0) {
                nice.push_back(l1[p1]);
                cur = l1[p1].first;
                p1--;
            } else if (l1[p1].second < l2[p2].second) {
                if (l1[p1].second >= l2[p2].first) {
                    l2[p2].first = min(l2[p2].first, l1[p1].second);
                    p1--;
                } else {
                    nice.push_back(l2[p2]);
                    cur = l2[p2].first;
                    p2--;
                }
            } else {
                assert(l1[p1].second >= l2[p2].second);
                nice.push_back(l1[p1]);
                cur = l1[p1].first;
                p1--;
            }
            while (p1 >= 0 && l1[p1].first >= cur) p1--;
            if (p1 >= 0) l1[p1].second = min(l1[p1].second, cur - 1);
            while (p2 >= 0 && l2[p2].first >= cur) p2--;
            if (p2 >= 0) l2[p2].second = min(l2[p2].second, cur - 1);
        }
        swap(restriction, nice);
    }

    return;
}

long long arrival_time(long long Y)
{
    auto yes = prev(upper_bound(restriction.begin(), restriction.end(), make_pair( Y, numeric_limits<long long>::max() )));
    if (yes != restriction.end()) Y = max(Y, yes->second);
    return Y + x * l;
}

• Subtask 0: 0 / 0
• Subtask 1: 0 / 9
• Subtask 2: 0 / 10
• Subtask 3: 0 / 20
• Subtask 4: 0 / 26
• Subtask 5: 0 / 35