Submission #1246739

#	Time	Username	Problem	Language	Result	Execution time	Memory
1246739		colossal_pepe	추월 (IOI23_overtaking)	C++17	100 / 100	645 ms	69432 KiB

overtaking

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

using ll = long long;

const ll INF = 3e18;

ll l, x;
int n, m;
vector<ll> s;
vector<vector<tuple<ll, ll, int>>> table;
vector<vector<ll>> et;
vector<vector<ll>> dp;

void init(int L, int N, vector<ll> T, vector<int> W, int X, int M, vector<int> S) {
    l = L, x = X;
    m = M;
    s.assign(S.begin(), S.end());
    table.resize(m, vector<tuple<ll, ll, int>>(0));
    for (int i = 0; i < N; i++) {
        if (W[i] <= x) continue;
        table[0].emplace_back(T[i], W[i], table[0].size());
    }
    n = table[0].size();
    if (n == 0) return;
    et.resize(m, vector<ll>(n));
    for (int i = 0; i < n; i++) {
        et[0][i] = get<0>(table[0][i]);
    }
    for (int i = 1; i < m; i++) {
        sort(table[i - 1].begin(), table[i - 1].end());
        table[i] = table[i - 1];
        for (int j = 0; j < n; j++) {
            auto &[t_nxt, w, idx] = table[i][j];
            t_nxt = et[i - 1][idx] + w * (s[i] - s[i - 1]);
            if (j) t_nxt = max(t_nxt, get<0>(table[i][j - 1]));
            et[i][idx] = get<0>(table[i][j]);
        }
    }
    sort(table[m - 1].begin(), table[m - 1].end());
    dp.resize(m, vector<ll>(n, -1));
    return;
}

ll calcT(ll y, int l, int r) {
    return y + x * (s[r] - s[l - 1]);
}

int nextIntersection(ll y, int L, int k) {
    int l = L + 1, r = m - 1;
    while (r - l > 1) {
        int mid = (l + r) / 2;
        if (calcT(y, L + 1, mid) <= get<0>(table[mid][k])) r = mid;
        else l = mid + 1;
    }
    for (int i = l; i <= r; i++) {
        if (calcT(y, L + 1, i) <= get<0>(table[i][k])) return i;
    }
    return m;
}

void update(vector<pair<int, int>> &dp_empty, ll arrive) {
    for (auto [i, k] : dp_empty) {
        dp[i][k] = arrive;
    }
}

ll arrival_time(ll y) {
    if (table[0].empty()) return y + x * (s[m - 1] - s[0]);
    int i = 0;
    vector<pair<int, int>> empty_dp;
    while (i < m) {
        // cerr << "HELLO " << y << endl;
        auto itr = lower_bound(table[i].begin(), table[i].end(), make_tuple(y, x, n));
        if (itr == table[i].begin()) {
            y = calcT(y, i + 1, m - 1);
            break;
        }
        itr = prev(itr);
        int k = itr - table[i].begin();
        int i_nxt = nextIntersection(y, i, k);
        if (i_nxt == m) {
            y = calcT(y, i + 1, m - 1);
            break;
        }
        // cerr << "WTF " << i_nxt << ' ' << calcT(y, i + 1, i_nxt) << ' ' << get<0>(table[i_nxt][k]) << endl;
        if (dp[i_nxt][k] != -1) {
            y = dp[i_nxt][k];
            break;
        }
        empty_dp.emplace_back(i_nxt, k);
        y = get<0>(table[i_nxt][k]);
        i = i_nxt;
    }
    update(empty_dp, y);
    // cerr << "ANSWER " << y << endl;
    return y;
}

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