Submission #1242771

#	Time	Username	Problem	Language	Result	Execution time	Memory
1242771		Zbyszek99	Overtaking (IOI23_overtaking)	C++20	100 / 100	1084 ms	92232 KiB

overtaking

#include "overtaking.h"
#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define ull unsigned long long
#define ff first
#define ss second
#define pii pair<int,int>
#define pll pair<long long, long long>
#define vi vector<int>
#define vl vector<long long>
#define pb push_back
#define rep(i, b) for(int i = 0; i < (b); ++i)
#define rep2(i,a,b) for(int i = a; i <= (b); ++i)
#define rep3(i,a,b,c) for(int i = a; i <= (b); i+=c)
#define count_bits(x) __builtin_popcountll((x))
#define all(x) (x).begin(),(x).end()
#define siz(x) (int)(x).size()
#define forall(it,x) for(auto& it:(x))
using namespace std;
const int INF = 1e9+50;
const ll INF_L = 1e18+40;
const ll MOD = 1e9+7;

ll L;
int n,m;
ll T[1001];
ll W[1001];
ll S[1001];
ll arr_time[1001][1001];
unordered_map<ll,ll> X_arrs[1001];
vl times[1001];
vl pref_max[1001];
ll X;

int nxt_overtake(int poz, ll time)
{
    int l = 0;
    int r = n-1;
    int cur_up = -1;
    while(l <= r)
    {
        int mid = (l+r)/2;
        if(times[poz][mid] < time)
        {
            cur_up = mid;
            l = mid+1;
        }
        else
        {
            r = mid-1;
        }
    }
    if(cur_up == -1) return m-1;
    l = poz;
    r = m-1;
    int ans = poz;
    while(l <= r)
    {
        int mid = (l+r)/2;
        if(times[mid][cur_up] < time + (S[mid]-S[poz]) * X)
        {
            ans = mid;
            l = mid+1;
        }
        else
        {
            r = mid-1;
        }
    }
    return ans;
}

ll nxt_after_overtake(int poz, ll time)
{
    int l = 0;
    int r = n-1;
    int my_ind = 0;
    while(l <= r)
    {
        int mid = (l+r)/2;
        if(times[poz][mid] < time)
        {
            my_ind = mid;
            l = mid+1;
        }
        else
        {
            r = mid-1;
        }
    }
    return pref_max[poz][my_ind];
}

void init(int L2, int N2, vl T2, vi W2, int X2, int M2, vi S2)
{
    L = L2;
    n = N2;
    rep(i,n) T[i] = T2[i];
    rep(i,n) W[i] = W2[i];
    X = X2;
    m = M2;
    rep(i,m) S[i] = S2[i];
    vector<pll> bus;
    rep(i,n) if(W[i] > X) bus.pb({W[i],T[i]});
    sort(all(bus));
    reverse(all(bus));
    n = 0;
    forall(it,bus)
    {
        W[n] = it.ff;
        T[n] = it.ss;
        n++;
    }
    rep(i,n)
    {
        arr_time[i][0] = T[i];
        times[0].pb(T[i]);
    }
    sort(all(times[0]));
    rep2(j,1,m-1)
    {
        vector<pll> arrs;
        rep(i,n) arrs.pb({arr_time[i][j-1],-i});
        sort(all(arrs));
        ll max_time = 0;
        forall(it,arrs)
        {
            int i = -it.ss;
            arr_time[i][j] = max(arr_time[i][j-1] + (S[j]-S[j-1]) * W[i],max_time);
            max_time = max(max_time,arr_time[i][j]);
        }
        rep(i,n) times[j].pb(arr_time[i][j]);
        sort(all(times[j]));
    }
    rep(j,m-1)
    {
        ll cur_max = 0;
        vector<pll> arrs;
        rep(i,n) arrs.pb({arr_time[i][j],arr_time[i][j+1]});
        sort(all(arrs));
        forall(it,arrs)
        {
            cur_max = max(cur_max,it.ss);
            pref_max[j].pb(cur_max);
        }
    }
    forall(it,times[m-1])
    {
        X_arrs[m-1][it] = it;
    }
    for(int j = m-2; j >= 0; j--)
    {
        rep(i,n)
        {
            int nxt = nxt_overtake(j,arr_time[i][j]);
            if(nxt == m-1)
            {
                X_arrs[j][arr_time[i][j]] = arr_time[i][j] + (S[m-1] - S[j]) * X;
            }
            else
            {
                X_arrs[j][arr_time[i][j]] = X_arrs[nxt+1][nxt_after_overtake(nxt,arr_time[i][j] + (S[nxt]-S[j]) * X)];
            }
        }
    }
}

ll arrival_time(ll time_)
{
    int nxt = nxt_overtake(0,time_);
    if(nxt == m-1) return time_ + L*X;
    return X_arrs[nxt+1][nxt_after_overtake(nxt,time_ + S[nxt] * X)];
}

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