Submission #1218481

#	Time	Username	Problem	Language	Result	Execution time	Memory
1218481		vanea	Overtaking (IOI23_overtaking)	C++20	0 / 100	0 ms	580 KiB

overtaking

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

const int mxN = 1e3+10;
int l, n;vector<ll> t; vector<int> w; int x; int m; vector<int> s;
array<ll, 2> st[mxN][4*mxN];

void upd(int v, int node, int l, int r, int k, ll t, ll w) {
    if(l == r && l == k) {
        st[v][node] = {t, w};
        return ;
    }
    if(l > k || r < k) return ;
    int mid = (l+r)/2;
    upd(v, node*2, l, mid, k, t, w);
    upd(v, node*2+1, mid+1, r, k, t, w);
    st[v][node] = max(st[v][node*2], st[v][node*2+1]);
}

int qry(int v, int node, int l, int r, ll x) {
    if(l == r) return l;
    int mid = (l+r)/2;
    if(st[v][node*2][0] >= x) return qry(v, node*2, l, mid, x);
    else return qry(v, node*2+1, mid+1, r, x);
}

ll qry1(int v, int node, int l, int r, int l1, int r1) {
    if(l1 <= l && r <= r1) return st[v][node][0];
    if(l1 > r || r1 < l) return 0;
    int mid = (l+r)/2;
    return max(qry1(v, node*2, l, mid, l1, r1), qry1(v, node*2+1, mid+1, r, l1, r1));
}

void init(int L, int N, vector<ll> T, vector<int> W, int X, int M, vector<int> S) {
    l = L; n = N; t = T; w = W; x = X; m = M; s = S;
    set<array<ll, 3>> buses;
    for(int i = 0; i < n; i++) {
        buses.insert({t[i], w[i], i});
    }
    int idx = 0;
    for(auto [t, w, _] : buses) {
        upd(0, 1, 0, n-1, idx, t, w);
        ++idx;
    }
    for(int i = 1; i < m; i++) {
        set<array<ll, 3>> nxt;
        for(auto [t, w, idx] : buses) {
            ll f = t + w * (s[i] - s[i-1]);
            ll s;
            if(nxt.empty()) s = 0;
            else {
                auto it = prev(nxt.end());
                s = (*it)[0];
            }
            ll now = max(f, s);
            nxt.insert({now, w, idx});
        }
        swap(buses, nxt);
        idx = 0;
        for(auto [t, w, _] : buses) {
            upd(i, 1, 0, n-1, idx, t, w);
            ++idx;
        }
    }
}

ll calculate_arrival_time(ll Y) {
    ll last = Y, cnt = Y > st[0][1][0] ? n : qry(0, 1, 0, n-1, Y);
    for(int j = 1; j < m; j++) {
        ll f = last + x * (s[j] - s[j-1]);
        ll s = qry1(j, 1, 0, n-1, 0, cnt-1);
        last = max(f, s);
        cnt = last > st[j][1][0] ? n : qry(j, 1, 0, n-1, last);
        if(j == m-1) return last;
    }
}

ll arrival_time(ll Y) {
    return calculate_arrival_time(Y);
}

Compilation message (stderr)

overtaking.cpp: In function 'll calculate_arrival_time(ll)':
overtaking.cpp:78:1: warning: control reaches end of non-void function [-Wreturn-type]
   78 | }
      | ^

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