Submission #848161

#	Time	Username	Problem	Language	Result	Execution time	Memory
848161		haxorman	Overtaking (IOI23_overtaking)	C++17	9 / 100	2 ms	10840 KiB

overtaking

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

#define int long long

const int mxN = 1007;

int n, len, x, m, y, t[mxN][mxN], e[mxN][mxN], gt[mxN][mxN];
vector<int> s, vec;
vector<deque<pair<int,int>>> prefmx;
vector<pair<int,int>> arr;

int cur_ind;
bool cmp(int a, int b) {
    if (t[a][cur_ind] == t[b][cur_ind]) {
        return arr[a].second < arr[b].second;
    }
    return t[a][cur_ind] < t[b][cur_ind];
}

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)
{
    n = N, len = L, m = M, x = X;

    vector<int> inds;
    for (int i = 0; i < n; ++i) {
        arr.push_back({T[i], W[i]});
        vec.push_back(T[i]);

        inds.push_back(i);
    }
    sort(arr.begin(), arr.end());
    sort(vec.begin(), vec.end());
    for (int i = 0; i < n; ++i) {
        t[i][0] = arr[i].first;
    }

    for (int i = 0; i < m; ++i) {
        s.push_back(S[i]);
    }
    
    prefmx.push_back({{len, 0}});
    for (int i = 1; i < n; ++i) { // y = arr[i].second * x + arr[i].first;
        int del = 0, dist = len;
        deque<pair<int,int>> cur = prefmx.back();
        for (int j = 0; j < cur.size(); ++j) {
            int prv = cur[j].second;
            int cross;
            if (arr[i].second != arr[prv].second) {
                cross = (arr[prv].first - arr[i].first) /
                        (arr[i].second - arr[prv].second);
            }
            else {
                cross = -1;
            }

            if (cross < 0 || cross >= cur[j].first) {
                del++;
            }
            else {
                /*
                if (i == 3) {
                    cout << arr[i].first << ' ' << arr[i].second << "\n";
                    cout << arr[prv].first << ' ' << arr[prv].second << "\n";
                    cout << cur[j].first << ' ' << cur[j].second << "\n";
                }
                */
                dist = cross;
                break;
            }
        }

        while (del--) {
            cur.pop_front();
        }
        
        cur.push_front({dist, i});
        prefmx.push_back(cur);
    }
    
    for (int j = 1; j < m; ++j) {
        for (int i = 0; i < n; ++i) {
            e[i][j] = t[i][j - 1] + arr[i].second * (s[j] - s[j - 1]);
        }
        cur_ind = j - 1;
        sort(inds.begin(), inds.end(), cmp);
        
        int mx = 0;
        for (auto i : inds) {
            mx = max(mx, e[i][j]);
            t[i][j] = mx;
        }
    }
    
    for (int i = 0; i < n; ++i) {
        gt[i][m - 1] = t[i][m - 1];
    }
    
    for (int j = m - 2; j >= 0; --j) {
        cur_ind = j;
        sort(inds.begin(), inds.end(), cmp);
        
        int mx = 0;
        for (auto i : inds) {
            gt[i][j] = max(mx, t[i][j] + x * (len - s[j]));
            mx = max(mx, gt[i][j + 1]);
        }
    }
}

long long arrival_time(long long Y)
{
    y = Y;
    
    int ind = upper_bound(vec.begin(), vec.end(), y) - vec.begin();
    if (!ind) {
        return y + x * len;
    }
    ind--;

    int lb = 0, rb = len, res = -1;
    while (lb <= rb) {
        int mb = (lb + rb) / 2;

        int l = 0, r = prefmx[ind].size() - 1, id = 0;
        while (l <= r) {
            int mid = (l + r) / 2;

            if (prefmx[ind][mid].first >= mb) {
                r = mid - 1;
                id = prefmx[ind][mid].second;
            }
            else {
                l = mid + 1;
            }
        }

        int vala = y + mb * x, valb = arr[id].first + mb * arr[id].second;
        if (valb >= vala) {
            rb = mb - 1;
            res = gt[id][lower_bound(s.begin(), s.end(), mb) - s.begin()];
        }
        else {
            lb = mb + 1;
        }
    }

    if (res == -1) {
        return y + x * len;
    }
    return res;
}

Compilation message (stderr)

overtaking.cpp: In function 'void init(int32_t, int32_t, std::vector<long long int>, std::vector<int>, int32_t, int32_t, std::vector<int>)':
overtaking.cpp:47:27: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::deque<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   47 |         for (int j = 0; j < cur.size(); ++j) {
      |                         ~~^~~~~~~~~~~~

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