#include <bits/stdc++.h>
#include <ext/pb_ds/priority_queue.hpp>
using namespace std;
#define rep(i, a, b) for (auto i = (a); i < (b); ++i)
#define all(x...) begin(x), end(x)
using ll = long long;
template<class T> bool ckmin(T &a, const T &b) { return a > b ? a = b, 1 : 0; }
template<class T> bool ckmax(T &a, const T &b) { return a < b ? a = b, 1 : 0; }
const int N = 1 << 9, M = 1 << 16;
const ll inf = 1e18;
int n;
ll d[N][N];
int a[M], b[M], w[M], c[M];
vector<int> g[N];
bool onPath[M], vis[N];
bool dfs(int u, int t) {
if (u == t) return true;
vis[u] = true;
for (int e : g[u]) {
assert(a[e] == u);
int v = b[e];
assert(d[u][t] <= w[e] + d[v][t]);
if (!vis[v] && w[e] + d[v][t] == d[u][t] && dfs(v, t))
return onPath[e] = true;
}
return false;
}
using pq_t = __gnu_pbds::priority_queue<pair<ll, int>, greater<>>;
pq_t::point_iterator it[N];
ll dij(int s, int t) {
pq_t pq;
rep(u, 0, n) if (u != s) it[u] = pq.push({inf, u});
it[s] = pq.push({0, s});
while (!pq.empty()) {
int u; ll dist;
tie(u, dist) = pq.top();
pq.pop(); it[u] = nullptr;
if (u == t) return dist;
for (int e : g[u]) {
int v = b[e];
if (it[v]) {
dist += w[e];
if (dist < it[v]->first)
pq.modify(it[v], {dist, v});
dist -= w[e];
}
}
}
return inf;
}
signed main() {
cin.tie(nullptr)->sync_with_stdio(false);
int m; cin >> n >> m;
rep(u, 0, n) rep(v, 0, n) d[u][v] = inf;
rep(u, 0, n) d[u][u] = 0;
rep(e, 0, m) {
cin >> a[e] >> b[e] >> w[e] >> c[e], --a[e], --b[e];
ckmin(d[a[e]][b[e]], ll(w[e]));
g[a[e]].push_back(e);
}
rep(w, 0, n)
rep(u, 0, n)
rep(v, 0, n)
ckmin(d[u][v], d[u][w] + d[w][v]);
int s = 0, t = n - 1;
fill(vis, vis + n, 0); dfs(s, t);
fill(vis, vis + n, 0); dfs(t, s);
ll ans = d[s][t] + d[t][s];
rep(e, 0, m) {
if (!onPath[e]) {
ll to = min(d[s][t], d[s][b[e]] + w[e] + d[a[e]][t]);
ll fr = min(d[t][s], d[t][b[e]] + w[e] + d[a[e]][s]);
ckmin(ans, c[e] + to + fr);
} else {
g[a[e]].erase(find(all(g[a[e]]), e));
swap(a[e], b[e]);
g[a[e]].push_back(e);
ckmin(ans, c[e] + dij(0, n - 1) + dij(n - 1, 0));
g[a[e]].pop_back();
swap(a[e], b[e]);
g[a[e]].push_back(e);
}
}
cout << (ans < inf ? ans : -1);
}
Compilation message
ho_t4.cpp: In function 'll dij(int, int)':
ho_t4.cpp:51:12: error: could not convert 'it[v]' from '__gnu_pbds::priority_queue<std::pair<long long int, int>, std::greater<void> >::point_iterator' {aka '__gnu_pbds::detail::left_child_next_sibling_heap_node_point_const_iterator_<__gnu_pbds::detail::left_child_next_sibling_heap_node_<std::pair<long long int, int>, __gnu_pbds::null_type, std::allocator<char> >, std::allocator<char> >'} to 'bool'
51 | if (it[v]) {
| ~~~~^
| |
| __gnu_pbds::priority_queue<std::pair<long long int, int>, std::greater<void> >::point_iterator {aka __gnu_pbds::detail::left_child_next_sibling_heap_node_point_const_iterator_<__gnu_pbds::detail::left_child_next_sibling_heap_node_<std::pair<long long int, int>, __gnu_pbds::null_type, std::allocator<char> >, std::allocator<char> >}
