#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) (int)a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x,y) ((x+y-1)/(y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl
#define rep(i,n) for(int i = 0; i < n; ++i)
#define rep1(i,n) for(int i = 1; i <= n; ++i)
#define rev(i,s,e) for(int i = s; i >= e; --i)
#define trav(i,a) for(auto &i : a)
template<typename T>
void amin(T &a, T b) {
a = min(a,b);
}
template<typename T>
void amax(T &a, T b) {
a = max(a,b);
}
#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif
/*
*/
const int MOD = 1e9 + 7;
const int N = 200 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;
const int M = 5e4 + 5;
vector<array<ll,3>> adj[N];
vector<pll> adj2[N];
vector<bool> bridge(M);
vector<bool> vis(N);
vector<ll> tin(N), low(N);
ll timer = 1;
void dfs1(ll u, ll p){
vis[u] = 1;
tin[u] = low[u] = timer++;
for(auto [v,id] : adj2[u]){
if(v == p) conts;
if(vis[v]){
amin(low[u],tin[v]);
}
else{
dfs1(v,u);
amin(low[u],low[v]);
if(low[v] > tin[u]){
bridge[id] = 1;
}
}
}
}
void dfs2(ll u, ll p, ll ignore){
vis[u] = 1;
for(auto [v,id] : adj2[u]){
if(vis[v]) conts;
if(id == ignore) conts;
dfs2(v,u,ignore);
}
}
void solve(int test_case)
{
ll n,m; cin >> n >> m;
vector<array<ll,4>> edges(m+5);
rep1(i,m){
ll u,v,w,d; cin >> u >> v >> w >> d;
adj[u].pb({v,w,i}), adj[v].pb({u,w,i});
edges[i] = {u,v,w,d};
}
auto dijkstra = [&](ll s, ll flipped){
vector<ll> dis(n+5,inf2);
dis[s] = 0;
rep1(i,n) vis[i] = 0;
rep1(iter,n){
pll best = {inf2,inf2};
rep1(u,n){
if(vis[u]) conts;
pll px = {dis[u],u};
amin(best,px);
}
ll u = best.ss;
vis[u] = 1;
for(auto [v,w,id] : adj[u]){
if(id != flipped){
if(edges[id][0] == u){
amin(dis[v],dis[u]+w);
}
}
else{
if(edges[id][0] == v){
amin(dis[v],dis[u]+w);
}
}
}
}
return dis;
};
auto dijkstra_rev = [&](ll s){
vector<ll> dis(n+5,inf2);
dis[s] = 0;
rep1(i,n) vis[i] = 0;
rep1(iter,n){
pll best = {inf2,inf2};
rep1(u,n){
if(vis[u]) conts;
pll px = {dis[u],u};
amin(best,px);
}
ll u = best.ss;
vis[u] = 1;
for(auto [v,w,id] : adj[u]){
if(edges[id][0] == v){
amin(dis[v],dis[u]+w);
}
}
}
return dis;
};
auto dis1 = dijkstra(1,-1);
auto disn = dijkstra(n,-1);
auto dis1_rev = dijkstra_rev(1);
auto disn_rev = dijkstra_rev(n);
rep1(u,n){
for(auto [v,w,id] : adj[u]){
if(edges[id][0] == u){
if(dis1[u]+w == dis1[v]){
adj2[u].pb({v,id});
}
}
}
}
auto go = [&](ll s){
fill(all(vis),0);
dfs2(s,-1,-1);
ll reachable = count(all(vis),1);
rep1(i,m){
fill(all(vis),0);
dfs2(1,-1,i);
ll cnt = count(all(vis),1);
if(cnt != reachable){
bridge[i] = 1;
}
}
};
go(1);
rep1(i,n) adj2[i].clear();
rep1(u,n){
for(auto [v,w,id] : adj[u]){
if(edges[id][0] == u){
if(disn[u]+w == disn[v]){
adj2[u].pb({v,id});
}
}
}
}
timer = 1;
fill(all(vis),0);
go(n);
assert(count(all(bridge),1) <= 4*n);
ll ans = inf2;
amin(ans,dis1[n]+disn[1]);
rep1(i,m){
auto [u,v,w,d] = edges[i];
if(bridge[i]){
ll cost = d+dijkstra(1,i)[n]+dijkstra(n,i)[1];
amin(ans,cost);
}
else{
ll sp_1_n = min(dis1[n],dis1[v]+w+disn_rev[u]);
ll sp_n_1 = min(disn[1],disn[v]+w+dis1_rev[u]);
ll cost = d+sp_1_n+sp_n_1;
amin(ans,cost);
if(cost == 1){
debug(i);
debug(sp_1_n);
debug(sp_n_1);
debug(disn[1]);
}
}
}
if(ans == inf2) ans = -1;
cout << ans << endl;
}
int main()
{
fastio;
int t = 1;
// cin >> t;
rep1(i, t) {
solve(i);
}
return 0;
}
Compilation message
ho_t4.cpp: In function 'void solve(int)':
ho_t4.cpp:46:18: warning: statement has no effect [-Wunused-value]
46 | #define debug(x) 42
| ^~
ho_t4.cpp:231:17: note: in expansion of macro 'debug'
231 | debug(i);
| ^~~~~
ho_t4.cpp:46:18: warning: statement has no effect [-Wunused-value]
46 | #define debug(x) 42
| ^~
ho_t4.cpp:232:17: note: in expansion of macro 'debug'
232 | debug(sp_1_n);
| ^~~~~
ho_t4.cpp:46:18: warning: statement has no effect [-Wunused-value]
46 | #define debug(x) 42
| ^~
ho_t4.cpp:233:17: note: in expansion of macro 'debug'
233 | debug(sp_n_1);
| ^~~~~
ho_t4.cpp:46:18: warning: statement has no effect [-Wunused-value]
46 | #define debug(x) 42
| ^~
ho_t4.cpp:234:17: note: in expansion of macro 'debug'
234 | debug(disn[1]);
| ^~~~~
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
6 ms |
604 KB |
Output is correct |
| 2 |
Correct |
27 ms |
348 KB |
Output is correct |
| 3 |
Runtime error |
4 ms |
872 KB |
Execution killed with signal 6 |
| 4 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Runtime error |
113 ms |
11052 KB |
Execution killed with signal 6 |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
8 ms |
600 KB |
Output is correct |
| 2 |
Correct |
25 ms |
348 KB |
Output is correct |
| 3 |
Execution timed out |
1073 ms |
5012 KB |
Time limit exceeded |
| 4 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
6 ms |
604 KB |
Output is correct |
| 2 |
Correct |
27 ms |
348 KB |
Output is correct |
| 3 |
Runtime error |
4 ms |
872 KB |
Execution killed with signal 6 |
| 4 |
Halted |
0 ms |
0 KB |
- |
