#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
#define pb push_back
#define ff first
#define ss second
#define arr3 array<int, 3>
#define arr4 array<ll, 4>
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n, m; cin>>n>>m;
vector<arr3> g[n + 1];
vector<map<int, int>> mp(n + 1);
while (m--){
int x, y, c, w; cin>>x>>y>>c>>w;
g[x].pb({y, c, w});
g[y].pb({x, c, w});
mp[x][c]++; mp[y][c]++;
}
queue<arr4> q; q.push({1, 0, 0, 0});
vector<map<int, ll>> dist(n + 1);
dist[1][0] = 0;
while (!q.empty()){
auto [v, k, P, ds] = q.front(); q.pop();
for (auto [u, c, w]: g[v]){
int cc = mp[v][c] - (c == k);
ll f = ds + w;
if (dist[u].find(c) == dist[u].end()){
dist[u][c] = f;
q.push({u, c, v, f});
}
else if (f < dist[u][c]){
dist[u][c] = f;
q.push({u, c, v, f});
}
if (u == P && k){
assert(c == k);
if (dist[u].find(k) == dist[u].end()){
dist[u][k] = ds;
q.push({u, k, v, ds});
}
else if (ds < dist[u][k]){
dist[u][k] = ds;
q.push({u, k, v, ds});
}
}
if (cc <= 1){
ll f = ds;
if (dist[u].find(0) == dist[u].end()){
dist[u][0] = f;
q.push({u, 0, v, f});
}
else if (f < dist[u][0]){
dist[u][0] = f;
q.push({u, 0, v, f});
}
}
}
}
if (dist[n].empty()){
cout<<-1<<"\n";
}
else {
ll out = 1e18;
for (auto [x, y]: dist[n]) out = min(out, y);
cout<<out<<"\n";
}
}
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |