Submission #500276

#	Time	Username	Problem	Language	Result	Execution time	Memory
500276		couplefire	Robot (JOI21_ho_t4)	C++17	0 / 100	3047 ms	28436 KiB

Main

#include <bits/stdc++.h>
using namespace std;
#define ll long long

const int N = 100005;
const ll INF = 0x3f3f3f3f3f3f3f3f;

int n, m;
vector<array<int, 3>> adj[N];
map<int, vector<int>> cadj[N];
ll dp1[N]; map<int, ll> dp2[N];

int main(){
    // freopen("a.in", "r", stdin);
    cin.tie(0)->sync_with_stdio(0);
    cin >> n >> m;
    for(int i = 0; i<m; ++i){
        int u, v, c, p;
        cin >> u >> v >> c >> p;
        adj[u].push_back({v, c, p});
        adj[v].push_back({u, c, p});
        cadj[u][c].push_back(v);
        cadj[v][c].push_back(u);
    } 
    memset(dp1, INF, sizeof dp1);
    dp1[1] = 0;
    priority_queue<array<ll, 3>> pq;
    pq.push({0, 1, 0});
    while(pq.size()){
        auto [val, v, c] = pq.top();
        pq.pop();
        if(c){
            int u = (cadj[v][c][0]==v?cadj[v][c][1]:cadj[v][c][0]);
            if(val<dp1[u])
                dp1[u] = val, pq.push({val, u, 0});
        } else{
            for(auto [u, c, p] : adj[v]){
                if(!dp2[u].count(c) || val+p<dp2[u][c])
                    dp2[u][c] = val+p, pq.push({dp2[u][c], u, c});
                if(val+p<dp1[u])
                    dp1[u] = val+p, pq.push({dp1[u], u, 0});
                if((int)cadj[v][c].size()==1 && val<dp1[u])
                    dp1[u] = val, pq.push({dp1[u], u, 0});
            }
        }
    }
    cout << (dp1[n]==INF?-1:dp1[n]) << '\n';
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:25:17: warning: overflow in conversion from 'long long int' to 'int' changes value from '4557430888798830399' to '1061109567' [-Woverflow]
   25 |     memset(dp1, INF, sizeof dp1);
      |                 ^~~

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