Submission #841498

#	Time	Username	Problem	Language	Result	Execution time	Memory
841498		model_code	Overtaking (IOI23_overtaking)	C++17	65 / 100	3581 ms	21852 KiB

overtaking

// time_limit/sol_db_tle1.cpp

#include "overtaking.h"
#include <bits/stdc++.h>
#define all(x) (x).begin(), (x).end()
#define lsb(x) (x) & (-x)
using namespace std;

const int maxN = 1001;
typedef long long ll;

int n, m, x, ord[maxN][maxN];
ll arrive[maxN][maxN], premax[maxN][maxN];

vector <int> ind, w, s;
vector <ll> t;

map <ll, ll> ans[maxN];

void init(int L, int N, std::vector<long long> T, std::vector<int> W, int X, int M, std::vector<int> S)
{
    n = N, m = M, x = X, t = T, w = W, s = S;

    vector <int> inds;
    for (int i = 0; i < N; ++i) {
        arrive[0][i] = T[i];
        inds.push_back(i);
    }
    auto order_buses = [&](int j) {
        sort(all(inds), [&](int x, int y) {
            return arrive[j][x] < arrive[j][y];
        });
        for (int i = 0; i < N; ++i) {
            ord[j][i] = inds[i];
        }
    };
    for (int j = 1; j < M; ++j) {
        ll pre = 0, lpre = 0;
        order_buses(j - 1);
        for (int i = 0; i < N; ++i) {
            if (i && arrive[j - 1][inds[i]] != arrive[j - 1][inds[i - 1]]) {
                lpre = pre;
            }
            arrive[j][inds[i]] = max(arrive[j - 1][inds[i]] + 1ll * W[inds[i]] * (S[j] - S[j - 1]), lpre);
            premax[j][i] = pre = max(pre, arrive[j][inds[i]]);
        }
    }
    order_buses(M - 1);
}

ll calc(int j, ll y) {
    if (ans[j].count(y)) {
        return ans[j][y];
    }
    if (j == m) {
        return ans[j][y] = y;
    }
    ll curt = y;
    while (j < m) {
        int l = 0;
        int r = n;
        while (l < r) {
            int q = l + r >> 1;
            if (arrive[j - 1][ord[j - 1][q]] < curt) {
                l = q + 1;
            } else {
                r = q;
            }
        }
        curt = max(curt + 1ll * x * (s[j] - s[j - 1]), l? premax[j][l - 1]: 0);
        if (curt == l? premax[j][l - 1]: 0) {
            return ans[j][y] = calc(j + 1, curt);
        } else {
            j++;
        }
    }
    return curt;
}

long long arrival_time(long long y)
{
    return calc(1, y);
}

Compilation message (stderr)

overtaking.cpp: In function 'll calc(int, ll)':
overtaking.cpp:63:23: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   63 |             int q = l + r >> 1;
      |                     ~~^~~

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