Submission #489301

#	Time	Username	Problem	Language	Result	Execution time	Memory
489301		Jarif_Rahman	Robot (JOI21_ho_t4)	C++17	100 / 100	843 ms	102484 KiB

Main

#include <bits/stdc++.h>
#define pb push_back
#define f first
#define sc second
using namespace std;
typedef long long int ll;
typedef string str;
const ll inf = 1e17;
int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int n, m; cin >> n >> m;
    vector<vector<array<int, 3>>> v(n);
    for(int i = 0; i < m; i++){
        int a, b, c, p; cin >> a >> b >> c >> p; a--, b--;
        v[a].pb({b, c, p});
        v[b].pb({a, c, p});
    }
    vector<pair<int, int>> nodes;
    map<pair<int, int>, int> node_id;
    for(int i = 0; i < n; i++) nodes.pb({i, -1});
    for(int i = 0; i < n; i++){
        for(auto [x, c, p]: v[i]) nodes.pb({i, x});
    }
    for(int i = 0; i < nodes.size(); i++) node_id[nodes[i]] = i;
    vector<vector<pair<int, ll>>> g(nodes.size());
    for(int i = 0; i < n; i++){
        unordered_map<int, ll> cost;
        for(auto [x, c, p]: v[i]) cost[c]+=p;
        for(auto [x, c, p]: v[i]){
            g[i].pb({x, min((ll)p, cost[c]-p)});
            g[i].pb({node_id[{x, i}], p});
        }
    }
    for(int i = 0; i < n; i++){
        unordered_map<int, vector<pair<int, int>>> mp;
        for(auto [x, c, p]: v[i]) mp[c].pb({p, x});
        for(auto [cc, ss]: mp){
            if(ss.size() < 2) continue;
            sort(ss.rbegin(), ss.rend());
            ll s = 0;
            for(auto [p, x]: ss) s+=p;
            for(int j = 0; j < ss.size(); j++){
                ll cur = s-ss[j].f;
                if(j == 0){
                    cur-=ss[1].f;
                    g[node_id[{i, ss[j].sc}]].pb({ss[1].sc, cur});
                }
                else{
                    cur-=ss[0].f;
                    g[node_id[{i, ss[j].sc}]].pb({ss[0].sc, cur});
                }
            }
        }
    }

    vector<ll> dis(nodes.size(), inf);
    vector<bool> bl(nodes.size(), 0);
    priority_queue<pair<ll, int>> pq;
    dis[0] = 0;
    pq.push({0, 0});
    while(!pq.empty()){
        int nd = pq.top().sc; pq.pop();
        if(bl[nd]) continue;
        bl[nd] = 1;
        for(auto [x, w]: g[nd]) if(dis[nd]+w < dis[x]){
            dis[x] = dis[nd]+w;
            pq.push({-dis[x], x});
        }
    }

    ll ans = inf;
    for(int i = 0; i < nodes.size(); i++) if(nodes[i].f == n-1) ans = min(ans, dis[i]);
    if(ans >= inf) ans = -1;
    cout << ans << "\n";
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:25:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   25 |     for(int i = 0; i < nodes.size(); i++) node_id[nodes[i]] = i;
      |                    ~~^~~~~~~~~~~~~~
Main.cpp:43:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   43 |             for(int j = 0; j < ss.size(); j++){
      |                            ~~^~~~~~~~~~~
Main.cpp:73:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   73 |     for(int i = 0; i < nodes.size(); i++) if(nodes[i].f == n-1) ans = min(ans, dis[i]);
      |                    ~~^~~~~~~~~~~~~~

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