Submission #390301

#	Time	Username	Problem	Language	Result	Execution time	Memory
390301		oleksg	Robot (JOI21_ho_t4)	C++14	34 / 100	3072 ms	81404 KiB

Main

#pragma GCC optimize("O2")
#include <fstream>
#include <string>
#include <iostream>
#include <bitset>
#include <math.h>
#include <string>
#include <algorithm>
#include <assert.h>
#include <bits/stdc++.h>
#include <vector>
#include <queue>
#include<stdio.h>
#include<ctype.h>
#define ll long long
using namespace std;


ll n, m;
struct con{
    ll d;
    ll color;
    ll cost;
};

vector<con> cons[200001];
map<ll, ll> cost[200001];
// how much to convert all nodes of a color to some other color

map<ll, ll> dist[200001];

map<ll, ll> used[200001];
//if node with color x was used

int main(){
    cin >> n >> m;
    ll one, two, three, four;
    for (int x = 0; x < m; x++){
        cin >> one >> two >> three >> four;
        cons[one - 1].push_back({two - 1, three, four});
        cons[two - 1].push_back({one - 1, three, four});
    }
    for (int x = 0; x < n; x++){
        for (int y = 0; y < cons[x].size(); y++){
            ll col = cons[x][y].color;
            ll cst = cons[x][y].cost;
            if (cost[x].find(col) == cost[x].end()){
                cost[x][col] = cst;
            } else {
                cost[x][col] += cst;
            }
        }
    }
    priority_queue<tuple<ll, ll, ll>> q;
    //cost, node, color
    q.push(make_tuple(0, 0, 0));
    while(q.size() > 0){
        ll node;
        ll cst;
        ll color;
        tie(cst, node, color) = q.top();
        used[node][color] = 1;
        q.pop();
        cst *= -1;
        if (color != 0){
            //we need to go to a node with the same color
            for (auto con: cons[node]){
                if (con.color == color){
                    if (used[con.d].find(0) == used[con.d].end()){
                        ll ncost = cst + cost[node][color] - con.cost;
                        if (dist[con.d].find(0) == dist[con.d].end() || dist[con.d][0] > ncost){
                            dist[con.d][0] = ncost;
                            q.push(make_tuple(-1 * ncost, con.d, 0));
                        }
                    }
                }
            }
        }
        else{
            //there are 3 things which we can do
            for (auto con: cons[node]){
                if (used[con.d].find(con.color) == used[con.d].end()){
                    //dont switch anything and make the next node switch
                    ll ncost = cst;
                    if (dist[con.d].find(con.color) == dist[con.d].end() || dist[con.d][con.color] > ncost){
                        dist[con.d][con.color] = ncost;
                        q.push(make_tuple(-1 * ncost, con.d, con.color));
                    }
                }
                if (used[con.d].find(0) == used[con.d].end()){
                    //switch everything but the connection
                    ll ncost = cst + cost[node][con.color] - con.cost;
                    if (dist[con.d].find(0) == dist[con.d].end() || dist[con.d][0] > ncost){
                        dist[con.d][0] = ncost;
                        q.push(make_tuple(-1 * ncost, con.d, 0));
                    }
                    //switch our node only
                    ncost = cst + con.cost;
                    if (dist[con.d].find(0) == dist[con.d].end() || dist[con.d][0] > ncost){
                        dist[con.d][0] = ncost;
                        q.push(make_tuple(-1 * ncost, con.d, 0));
                    }
                }
            }
        }
    }
    if (dist[n - 1].find(0) == dist[n - 1].end()){
        cout << -1 << "\n";
    }
    else{
        cout << dist[n - 1][0] << "\n";
    }
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:44:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<con>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   44 |         for (int y = 0; y < cons[x].size(); y++){
      |                         ~~^~~~~~~~~~~~~~~~

• Subtask 1: 34 / 34
• Subtask 2: 0 / 24
• Subtask 3: 0 / 42