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;
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef vector<int> vi;
#define pb push_back
const int MN = 202, MM = 5e4+5;
int N, M, i, j, x, y, w[MM], c[MM], u[MM], vs[MN], ban[MM], par[MN]; ll ans, dis[MN], a[MM][MN], b[MM][MN], cost[MM];
vector<pii> adj[MN], rev[MN];
vi tree; pii ed[MM];
void dij(int src,bool dir){
memset(par,-1,sizeof(par));
memset(vs,0,sizeof(vs));
for(i=1;i<=N;i++)
dis[i]=1LL<<55;
dis[src]=0;
int cur=src; ll mn;
while(cur!=-1){
vs[cur]=1;
if(dir==1){
for(auto v : adj[cur]){
if(ban[v.second]) continue;
if(dis[cur]+w[v.second]<dis[v.first]){
dis[v.first]=dis[cur]+w[v.second];
par[v.first]=v.second;
}
}
}
else{
for(auto v : rev[cur]){
if(ban[v.second]) continue;
if(dis[cur]+w[v.second]<dis[v.first]){
dis[v.first]=dis[cur]+w[v.second];
par[v.first]=v.second;
}
}
}
mn=1LL<<50; cur=-1;
for(i=1;i<=N;i++){
if(vs[i]) continue;
if(dis[i]<mn){
mn=dis[i];
cur=i;
}
}
}
for(i=1;i<=N;i++){
if(par[i]!=-1) u[par[i]]=1;
}
}
int main(){
mt19937 mt(time(0));
for(scanf("%d%d",&N,&M),i=1;i<=M;i++){
scanf("%d%d%d%d",&x,&y,&w[i],&c[i]);
ed[i]={x,y};
adj[x].pb({y,i});
rev[y].pb({x,i});
}
for(i=1;i<=N;i++){
shuffle(adj[i].begin(),adj[i].end(),mt);
shuffle(rev[i].begin(),rev[i].end(),mt);
}
for(int k=0;k<2;k++){
memset(u,0,sizeof(u));
dij(1,1^k);
tree.clear();
for(i=1;i<=M;i++){
if(u[i]) tree.pb(i);
else{
for(j=1;j<=N;j++)
a[i][j]=dis[j];
}
}
assert(tree.size()<=N);
for(auto v : tree){
ban[v]=1;
dij(1,1^k);
for(j=1;j<=N;j++)
a[v][j]=dis[j];
ban[v]=0;
}
memset(u,0,sizeof(u));
dij(N,k);
tree.clear();
for(i=1;i<=M;i++){
if(u[i]) tree.pb(i);
else{
for(j=1;j<=N;j++)
b[i][j]=dis[j];
}
}
assert(tree.size()<=N);
for(auto v : tree){
ban[v]=1;
dij(N,k);
for(j=1;j<=N;j++)
b[v][j]=dis[j];
ban[v]=0;
}
for(j=1;j<=M;j++){
if(!k) cost[j]+=min(a[j][N],a[j][ed[j].second]+w[j]+b[j][ed[j].first]);
else cost[j]+=min(a[j][N],a[j][ed[j].first]+w[j]+b[j][ed[j].second]);
}
}
dij(1,1);
ans+=dis[N];
dij(N,1);
ans+=dis[1];
for(j=1;j<=M;j++)
ans=min(ans,cost[j]+c[j]);
if(ans>(1LL<<50)) printf("-1\n");
else printf("%lld\n",ans);
return 0;
}
Compilation message (stderr)
In file included from /usr/include/c++/7/cassert:44:0,
from /usr/include/x86_64-linux-gnu/c++/7/bits/stdc++.h:33,
from ho_t4.cpp:1:
ho_t4.cpp: In function 'int main()':
ho_t4.cpp:79:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
assert(tree.size()<=N);
~~~~~~~~~~~^~~
ho_t4.cpp:97:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
assert(tree.size()<=N);
~~~~~~~~~~~^~~
ho_t4.cpp:58:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
for(scanf("%d%d",&N,&M),i=1;i<=M;i++){
~~~~~~~~~~~~~~~~~~~^~~~
ho_t4.cpp:59:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d%d%d%d",&x,&y,&w[i],&c[i]);
~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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