This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
using namespace std;
#define int long long
#define vi vector<int>
#define vii vector<vector<int>>
#define pii pair<int, int>
#define pb push_back
#define f first
#define s second
#define endl "\n"
const int linf = 1e15;
// -------------------------------------------------- Main Code --------------------------------------------------
const int N = 201, M = 50001;
int n, m;
set<pii> g[N];
vii edges;
map<pair<int, int>, bool> isShort;
void dijkstra(int source) {
priority_queue<pii, vector<pii>, greater<>> q;
vi vis(n+1, 0), dis(n+1, linf), par(n+1);
q.push({0, source});
dis[source] = 0;
vector<pii> from(n+1);
while (!q.empty()) {
pii f = q.top(); q.pop();
int src = f.s;
if (vis[src]) continue;
vis[src] = true;
for (auto child : g[src]) {
int ch = child.f, wt = child.s;
if (dis[ch] > dis[src] + wt) {
from[ch] = {src, ch};
par[ch] = src;
dis[ch] = dis[src] + wt;
q.push({dis[ch], ch});
}
}
}
for (int i = 1; i <= n; i++) {
isShort[from[i]] = true;
}
}
int get_dist(int s, int t) {
vi D(n+1, linf);
priority_queue<pii, vector<pii>, greater<pii>> pq;
D[s] = 0;
pq.emplace(0, s);
while (pq.size()) {
pii temp = pq.top(); int x = temp.f, u = temp.s;
pq.pop();
if (D[u] == x) {
for (pii child : g[u]) {
int v = child.f, wt = child.s;
if (D[v] > x + wt) {
pq.emplace(D[v] = x + wt, v);
}
}
}
}
return D[t];
}
void sol() {
cin >> n >> m;
vii dist(n+1, vi(n+1, linf));
for (int i = 1; i <= n; i++) dist[i][i] = 0;
for (int i = 1; i <= m; i++) {
int a, b, c, d; cin >> a >> b >> c >> d;
dist[a][b] = min(dist[a][b], c);
g[a].insert({b, c});
edges.pb({a, b, c, d});
}
dijkstra(1);
dijkstra(n);
for (int k = 1; k <= n; ++k) {
for (int i = 1; i <= n; ++i) {
for (int j = 1; j <= n; ++j) {
dist[i][j] = min(dist[i][j], dist[i][k] + dist[k][j]);
}
}
}
int ans = min(linf, dist[1][n] + dist[n][1]);
for (auto i : edges) {
int a = i[0], b = i[1], c = i[2], d = i[3];
if (isShort[{a, b}]) {
int a = i[0], b = i[1], c = i[2], d = i[3];
g[a].erase({b, c});
g[b].insert({a, c});
ans = min(ans, get_dist(1, n) + get_dist(n, 1) + d);
g[b].erase({a, c});
g[a].insert({b, c});
}
else {
int A = min(dist[1][n], dist[1][b] + c + dist[a][n]);
int B = min(dist[n][1], dist[n][b] + c + dist[a][1]);
if (A < linf && B < linf) {
ans = min(ans, A + B + d);
}
}
}
cout << (ans==linf?-1:ans) << endl;
}
signed main () {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int t = 1;
// cin >> t;
while (t--) {
sol();
}
return 0;
}
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