#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define ff first
#define ss second
const int nax = 205;
const int fax = 5e4 + 4;
const int INF = 1e9;
int n, m;
int seen[nax];
int sp1[nax], ps1[nax], sp2[nax], ps2[nax];
vector<int> adj[nax], rev_adj[nax];
int U[fax], V[fax], is_on_path[fax];
int C[fax];
ll D[fax];
int previ[nax][4];
int vis[nax][nax];
void calculate_sp(int up = -1, int vp = -1, int edg = -1)
{
priority_queue <pair<int,int>, vector<pair<int,int>>, greater<pair<int,int>>> pq;
for(int i = 1; i <= n; i++)
{
sp1[i] = ps1[i] = sp2[i] = ps2[i] = INF;
seen[i] = 0;
}
sp1[1] = ps1[1] = sp2[n] = ps2[n] = 0ll;
previ[1][0] = previ[1][1] = -1;
pq.push({0, 1});
while(!pq.empty())
{
pair<int,int> E = (pq.top());
pq.pop();
int node = E.ss;
if(seen[node])
continue;
seen[node] = 1;
int path = E.ff;
if(previ[node][0] != -1)
is_on_path[previ[node][0]] = 1;
for(auto e: adj[node])
{
if(e == edg)
continue;
int v = V[e];
if(sp1[v] <= path + C[e])
continue;
sp1[v] = path + C[e];
previ[v][0] = e;
pq.push({path + C[e], v});
}
if(node == vp)
{
int v = up;
if(sp1[v] <= path + C[edg])
continue;
sp1[v] = path + C[edg];
pq.push({path + C[edg], v});
}
}
for(int i= 1; i <= n; i++)
seen[i] = 0;
pq.push({0, 1});
while(!pq.empty())
{
pair<int,int> E = (pq.top());
pq.pop();
int node = E.ss;
if(seen[node])
continue;
seen[node] = 1;
int path = E.ff;
if(previ[node][1] != -1)
is_on_path[previ[node][1]] = 1;
for(auto e: rev_adj[node])
{
if(e == edg)
continue;
int v = U[e];
if(ps1[v] <= path + C[e])
continue;
ps1[v] = path + C[e];
pq.push({path + C[e], v});
}
if(node == up)
{
int v = vp;
if(ps1[v] <= path + C[edg])
continue;
ps1[v] = path + C[edg];
pq.push({path + C[edg], v});
}
}
previ[n][2] = previ[n][3] = -1;
for(int i =1; i <= n; i++)
seen[i] = 0;
pq.push({0, n});
while(!pq.empty())
{
pair<int,int> E = (pq.top());
pq.pop();
int node = E.ss;
if(seen[node])
continue;
seen[node] = 1;
int path = E.ff;
if(previ[node][2] != -1)
is_on_path[previ[node][2]] = 1;
for(auto e: adj[node])
{
if(e == edg)
continue;
int v = V[e];
if(sp2[v] <= path + C[e])
continue;
sp2[v] = path + C[e];
previ[v][2] = e;
pq.push({path + C[e], v});
}
if(node == vp)
{
int v = up;
if(sp2[v] <= path + C[edg])
continue;
sp2[v] = path + C[edg];
pq.push({path + C[edg], v});
}
}
for(int i =1; i <= n; i++)
seen[i] = 0;
pq.push({0, n});
while(!pq.empty())
{
pair<int,int> E = (pq.top());
pq.pop();
int node = E.ss;
if(seen[node])
continue;
seen[node] = 1;
int path = E.ff;
if(previ[node][3] != -1)
is_on_path[previ[node][3]] = 1;
for(auto e: rev_adj[node])
{
if(e == edg)
continue;
int v = U[e];
if(ps2[v] <= path + C[e])
continue;
ps2[v] = path + C[e];
previ[v][3] = e;
pq.push({path + C[e], v});
}
if(node == up)
{
int v = vp;
if(ps2[v] <= path + C[edg])
continue;
ps2[v] = path + C[edg];
pq.push({path + C[edg], v});
}
}
assert(sp1[1] == 0);
assert(sp2[n] == 0);
assert(sp1[n] == ps2[1]);
assert(sp2[1] == ps1[n]);
}
void solve()
{
cin >> n >> m;
vector<pair<int,int>> VEC;
for(int i = 0; i < m; i++)
{
cin >> U[i] >> V[i] >> C[i] >> D[i];
VEC.pb({C[i], i});
}
sort(all(VEC));
for(auto p: VEC)
{
int e = p.ss;
if(vis[U[e]][V[e]] == 2)
continue;
adj[U[e]].pb(e);
rev_adj[V[e]].pb(e);
vis[U[e]][V[e]]++;
}
calculate_sp();
vector<int> NON, YES;
for(int i = 0; i < m; i++)
{
if(is_on_path[i])
YES.pb(i);
else
NON.pb(i);
}
assert((int)(YES.size()) <= 4 * n);
ll ans = sp1[n] >= INF || sp2[1] >= INF? 2ll * INF: sp1[n] + sp2[1];
for(auto i: NON)
{
int u = U[i], v = V[i];
ll c = C[i], d = D[i];
ll un = sp1[n];
ll uV = sp1[v];
ll Un = ps2[u];
ll nu = sp2[1];
ll nV = sp2[v];
ll Uu = ps1[u];
if((un >= INF && uV + c + Un >= INF) || (nu >= INF && nV + c + Uu >= INF))
continue;
ll rep = d + min(un, uV + c + Un) + min(nu, nV + c + Uu);
ans = min(ans, rep);
}
for(auto i: YES)
{
calculate_sp(U[i], V[i], i);
if(sp1[n] >= INF || sp2[1] >= INF)
continue;
ans = min(ans, (ll)(sp1[n]) + (ll)(sp2[1]) + D[i]);
//cout << sp1[n] << ' ' << sp2[1] << '\n';
}
if(ans >= 2ll * INF)
cout << "-1";
else
cout << ans;
}
int32_t main()
{
ios::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
#ifndef ONLINE_JUDGE
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#endif
int tt = 1; // cin >> tt;
while(tt--)
solve();
}
Compilation message
ho_t4.cpp: In function 'int32_t main()':
ho_t4.cpp:248:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
248 | freopen("input.txt", "r", stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
ho_t4.cpp:249:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
249 | freopen("output.txt", "w", stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
340 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
340 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
340 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
340 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
