Submission #848338

#	Time	Username	Problem	Language	Result	Execution time	Memory
848338		haxorman	Overtaking (IOI23_overtaking)	C++17	19 / 100	7 ms	31580 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], pref[mxN][mxN];
vector<int> s, vec;
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]);
    }
    
    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;
        }
        
        mx = -1;
        int id = 0;
        for (int i = 0; i < n; ++i) {
            if (mx <= t[i][j]) {
                mx = t[i][j];
                id = i;
            }
            pref[i][j] = id;
        }
    }
    
    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 check = 0, prv = -1;
        for (int it1 = 0; it1 < n; ++it1) {
            int i = inds[it1];
            pair<int,int> mn = {LLONG_MAX, LLONG_MAX};
            for (int it2 = 0; it2 < it1; ++it2) {
                int k = inds[it2];

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

                    if (t[k][mb] >= t[i][j] + x * (s[mb] - s[j])) {
                        rb = mb - 1;
                        if (mb < mn.first || (mb == mn.first && t[k][mb] >= mn.second)) {
                            mn = {mb, t[k][mb]};
                            check = gt[k][mb];
                        }
                    }
                    else {
                        lb = mb + 1;
                    }
                }
            }
            gt[i][j] = max(check, t[i][j] + x * (len - s[j]));
        }
    }
}
 
long long arrival_time(long long Y)
{
    y = Y;
    
    int ind = lower_bound(vec.begin(), vec.end(), y) - vec.begin();
    if (!ind) {
        return y + x * len;
    }
    ind--;
 
    int lb = 0, rb = m - 1, res = -1;
    while (lb <= rb) {
        int mb = (lb + rb) / 2;
        int id = pref[ind][mb];
        
        int vala = y + s[mb] * x, valb = t[id][mb];
        if (valb >= vala) {
            rb = mb - 1;
            res = gt[id][mb];
        }
        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:81:45: warning: unused variable 'res' [-Wunused-variable]
   81 |                 int lb = j + 1, rb = m - 1, res = 0;
      |                                             ^~~
overtaking.cpp:74:24: warning: unused variable 'prv' [-Wunused-variable]
   74 |         int check = 0, prv = -1;
      |                        ^~~

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