Submission #993178

#	Time	Username	Problem	Language	Result	Execution time	Memory
993178		boris_mihov	Train (APIO24_train)	C++17	5 / 100	173 ms	31432 KiB

train

#include "train.h"
#include <algorithm>
#include <iostream>
#include <numeric>
#include <cassert>
#include <vector>
#include <queue>

typedef long long llong;
const int MAXN = 100000 + 10;
const llong INF = 4e18;
const int INTINF = 2e9;

int n, m, w;
struct Edge
{
    int from;
    int to;
    int cost;
    int begTime;
    int endTime;
};

Edge edges[MAXN];
struct Interval
{
    int from, to, cost;
};

int father[MAXN];
std::vector <int> endOfIntervals;
std::vector <std::pair <int,int>> intervals;
std::vector <std::pair <int,llong>> g[2 * MAXN];
std::vector <int> begining[MAXN];
std::vector <int> ending[MAXN];
llong dist[2 * MAXN];
bool vis[2 * MAXN];
int t[MAXN];

int intervalsToMe(int value)
{
    int l = -1, r = endOfIntervals.size(), mid;
    while (l < r - 1)
    {
        mid = l + r >> 1;
        if (endOfIntervals[mid] <= value) l = mid;
        else r = mid;
    }

    return r;
}

long long solve(int N, int M, int W, std::vector<int> T, std::vector<int> X, std::vector<int> Y,
                std::vector<int> A, std::vector<int> B, std::vector<int> C, std::vector<int> L,
                std::vector<int> R)
{
    n = N; m = M; w = W;
    for (int i = 0 ; i < m ; ++i)
    {
        X[i]++;
        Y[i]++;
        edges[i + 1] = {X[i], Y[i], C[i], A[i], B[i]};
        begining[X[i]].push_back(i + 1);
        ending[Y[i]].push_back(i + 1);
    }


    for (int i = 1 ; i <= n ; ++i)
    {
        t[i] = T[i - 1];
    }

    std::sort(L.begin(), L.end());
    std::sort(R.begin(), R.end());
    for (int i = 0 ; i < w ; ++i)
    {
        intervals.push_back({L[i], R[i]});
        endOfIntervals.push_back(R[i]);
    }
    
    int cnt = m;
    for (int i = 1 ; i <= n ; ++i)
    {
        std::sort(ending[i].begin(), ending[i].end(), [&](int x, int y)
        {
            return edges[x].endTime < edges[y].endTime;
        });

        std::sort(begining[i].begin(), begining[i].end(), [&](int x, int y)
        {
            return edges[x].begTime < edges[y].begTime;
        });

        for (int j = 0 ; j < begining[i].size() ; ++j)
        {
            father[begining[i][j]] = ++cnt;
            g[father[begining[i][j]]].push_back({begining[i][j], edges[begining[i][j]].cost + 1LL * intervalsToMe(edges[begining[i][j]].begTime - 1) * t[i]});
        }

        for (int j = 0 ; j + 1 < begining[i].size() ; ++j)
        {
            g[father[begining[i][j]]].push_back({father[begining[i][j + 1]], 0});
        }

        int ptr = begining[i].size();
        for (int j = (int)ending[i].size() - 1 ; j >= 0 ; --j)
        {
            while (ptr > 0 && edges[begining[i][ptr - 1]].begTime >= edges[ending[i][j]].endTime)
            {
                ptr--;
            }

            if (ptr < begining[i].size()) g[ending[i][j]].push_back({father[begining[i][ptr]], -1LL * intervalsToMe(edges[ending[i][j]].endTime) * t[i]});
        }
    }

    std::fill(dist + 1, dist + 1 + 2 * m, INF);
    std::priority_queue <std::pair <llong,int>> pq;
    for (const int &idx : begining[1])
    {
        int count = 0;
        for (const auto &[l, r] : intervals)
        {
            count += (r < edges[idx].begTime);
        }

        dist[idx] = edges[idx].cost + 1LL * count * t[1];
        pq.push({-dist[idx], idx});
    }

    while (pq.size())
    {
        auto [d, node] = pq.top();
        pq.pop();


        if (vis[node])
        {
            continue;
        }

        vis[node] = true;
        for (const auto &[u, ed] : g[node])
        {
            if (dist[u] > dist[node] + ed)
            {
                dist[u] = dist[node] + ed;
                pq.push({-dist[u], u});
            }
        }
    }

    llong min = INF;
    for (const auto &idx : ending[n])
    {
        int count = 0;
        for (const auto &[l, r] : intervals)
        {
            count += (edges[idx].endTime < l);
        }

        min = std::min(min, dist[idx]+ 1LL * count * t[n]);
    }

	if (min == INF) return -1;
    return min;
}

Compilation message (stderr)

train.cpp: In function 'int intervalsToMe(int)':
train.cpp:45:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   45 |         mid = l + r >> 1;
      |               ~~^~~
train.cpp: In function 'long long int solve(int, int, int, std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>)':
train.cpp:94:28: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   94 |         for (int j = 0 ; j < begining[i].size() ; ++j)
      |                          ~~^~~~~~~~~~~~~~~~~~~~
train.cpp:100:32: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  100 |         for (int j = 0 ; j + 1 < begining[i].size() ; ++j)
      |                          ~~~~~~^~~~~~~~~~~~~~~~~~~~
train.cpp:113:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  113 |             if (ptr < begining[i].size()) g[ending[i][j]].push_back({father[begining[i][ptr]], -1LL * intervalsToMe(edges[ending[i][j]].endTime) * t[i]});
      |                 ~~~~^~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 5
• Subtask 2: 5 / 5
• Subtask 3: 0 / 30
• Subtask 4: 0 / 60