Submission #889043

#	Time	Username	Problem	Language	Result	Execution time	Memory
889043		yeediot	Commuter Pass (JOI18_commuter_pass)	C++14	100 / 100	431 ms	34320 KiB

commuter_pass

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define F first
#define S second
#define all(x) x.begin(),x.end()
#define pii pair<int,int>
#define pb push_back
#define sz(x) (int)(x.size())
#define chmin(x,y) x=min(x,y)
#define chmax(x,y) x=max(x,y)
#define vi vector<int>
#define vp vector<pii>
#define vvi vector<vi>
#define ykh mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count())
void __print(int x) {cerr << x;}
void __print(float x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '\"' << x << '\"';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}

template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ','; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? "," : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#ifdef local
void setio(){freopen("/Users/iantsai/Library/Mobile Documents/com~apple~CloudDocs/cpp/Empty.md","r",stdin);}
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
void setio(){}
#define debug(x...)
#endif
void setIO(string s) {
    freopen((s + ".in").c_str(), "r", stdin);
    freopen((s + ".out").c_str(), "w", stdout);
}
struct line{
    int a,b;
    int operator()(const int x)const{
        return a*x+b;
    }
};
bool check(line l1,line l2,line l3){
    return (l3.b-l2.b)*(l1.a-l2.a)<=(l2.b-l1.b)*(l2.a-l3.a);
}
const int mxn=1e5+5;
vector<pii>adj[mxn];
int d[4][mxn];
int dp[2][mxn];
bool vis[mxn];
void dij(int st,int arr[]){
    fill(vis,vis+mxn,false);
    priority_queue<pii,vector<pii>,greater<pii>>pq;
    pq.push({0,st});
    while(sz(pq)){
        auto [dis,v]=pq.top();
        pq.pop();
        if(!vis[v]){
            arr[v]=dis;
            vis[v]=1;
            for(auto &u:adj[v]){
                pq.push({dis+u.S,u.F});
            }
        }
    }
}
int ans;
void dij2(int st,int ed,int arr[]){
    fill(vis,vis+mxn,false);
    fill(dp[0],dp[0]+mxn,1e18);
    fill(dp[1],dp[1]+mxn,1e18);
    priority_queue<pair<int,pii>,vector<pair<int,pii>>,greater<pair<int,pii>>>pq;
    pq.push({0,{st,0}});
    dp[0][0]=dp[1][0]=1e18;
    while(sz(pq)){
        int dis=pq.top().F;
        int v=pq.top().S.F;
        int pa=pq.top().S.S;
        pq.pop();
        if(!vis[v]){
            vis[v]=1;
            arr[v]=dis;
            dp[0][v]=min(d[0][v],dp[0][pa]);
            dp[1][v]=min(d[1][v],dp[1][pa]);
            for(auto u:adj[v]){
                pq.push({u.S+dis,{u.F,v}});
            }
        }
        else if(dis==arr[v]){
            if(min(d[0][v],dp[0][pa])+min(d[1][v],dp[1][pa])<=dp[0][v]+dp[1][v]){
                dp[0][v]=min(d[0][v],dp[0][pa]);
                dp[1][v]=min(d[1][v],dp[1][pa]);
            }
        }
        debug(v,dp[0][v]+dp[1][v]);
    }
    chmin(ans,dp[0][ed]+dp[1][ed]);
}
signed main(){
    setio();
    ios::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    int n,m,s,t,u,v;
    cin>>n>>m>>s>>t>>u>>v;
    for(int i=0;i<m;i++){
        int a,b,c;
        cin>>a>>b>>c;
        adj[a].pb({b,c});
        adj[b].pb({a,c});
    }
    dij(u,d[0]);
    dij(v,d[1]);
    ans=d[0][v];
    for(int i=1;i<=n;i++){
        debug(d[0][i]);
    }
    dij2(s,t,d[2]);
    dij2(t,s,d[3]);
    cout<<ans<<'\n';
}
 /*
 input:
  [node,dp[0][node]+dp[1][node]] = [6, 46]
  [node,dp[0][node]+dp[1][node]] = [3, 22]
  [node,dp[0][node]+dp[1][node]] = [1, 21]
  [node,dp[0][node]+dp[1][node]] = [8, 20]
  [node,dp[0][node]+dp[1][node]] = [4, 21]
  [node,dp[0][node]+dp[1][node]] = [3, 22]
  [node,dp[0][node]+dp[1][node]] = [9, 19]
  [node,dp[0][node]+dp[1][node]] = [1, 21]
  [node,dp[0][node]+dp[1][node]] = [1, 21]
  [node,dp[0][node]+dp[1][node]] = [8, 20]
  [node,dp[0][node]+dp[1][node]] = [5, 27]
  [node,dp[0][node]+dp[1][node]] = [2, 15]
  [node,dp[0][node]+dp[1][node]] = [2, 15]
  [node,dp[0][node]+dp[1][node]] = [2, 15]
  [node,dp[0][node]+dp[1][node]] = [5, 27]
  [node,dp[0][node]+dp[1][node]] = [6, 46]
  [node,dp[0][node]+dp[1][node]] = [9, 19]
  [node,dp[0][node]+dp[1][node]] = [8, 20]
  [node,dp[0][node]+dp[1][node]] = [4, 21]
  [node,dp[0][node]+dp[1][node]] = [3, 22]
  [node,dp[0][node]+dp[1][node]] = [1, 21]
  [node,dp[0][node]+dp[1][node]] = [10, 21]
  [node,dp[0][node]+dp[1][node]] = [3, 22]
  [node,dp[0][node]+dp[1][node]] = [10, 21]
  [node,dp[0][node]+dp[1][node]] = [7, 12]
  [node,dp[0][node]+dp[1][node]] = [7, 3]
  [node,dp[0][node]+dp[1][node]] = [6, 46]
  [node,dp[0][node]+dp[1][node]] = [1, 21]
  [node,dp[0][node]+dp[1][node]] = [2, 15]
  [node,dp[0][node]+dp[1][node]] = [8, 20]
  [node,dp[0][node]+dp[1][node]] = [5, 27]
  [node,dp[0][node]+dp[1][node]] = [8, 21]
  [node,dp[0][node]+dp[1][node]] = [9, 19]
  [node,dp[0][node]+dp[1][node]] = [1, 21]
  [node,dp[0][node]+dp[1][node]] = [8, 21]
  [node,dp[0][node]+dp[1][node]] = [8, 21]
  [node,dp[0][node]+dp[1][node]] = [4, 20]
  [node,dp[0][node]+dp[1][node]] = [3, 20]
  [node,dp[0][node]+dp[1][node]] = [1, 21]
  [node,dp[0][node]+dp[1][node]] = [1, 21]
  [node,dp[0][node]+dp[1][node]] = [2, 12]
  [node,dp[0][node]+dp[1][node]] = [2, 12]
  [node,dp[0][node]+dp[1][node]] = [2, 12]
  [node,dp[0][node]+dp[1][node]] = [5, 16]
  [node,dp[0][node]+dp[1][node]] = [6, 20]
  [node,dp[0][node]+dp[1][node]] = [3, 20]
  [node,dp[0][node]+dp[1][node]] = [10, 21]
  [node,dp[0][node]+dp[1][node]] = [9, 19]
  [node,dp[0][node]+dp[1][node]] = [4, 20]
  [node,dp[0][node]+dp[1][node]] = [3, 20]
  [node,dp[0][node]+dp[1][node]] = [8, 21]
  [node,dp[0][node]+dp[1][node]] = [10, 21]
  [node,dp[0][node]+dp[1][node]] = [7, 0]
  [node,dp[0][node]+dp[1][node]] = [1, 21]
  [node,dp[0][node]+dp[1][node]] = [7, 0]
  [node,dp[0][node]+dp[1][node]] = [3, 20]
  [node,dp[0][node]+dp[1][node]] = [6, 20]
  [node,dp[0][node]+dp[1][node]] = [1, 21]
  [node,dp[0][node]+dp[1][node]] = [5, 16]
  [node,dp[0][node]+dp[1][node]] = [8, 21]
  [node,dp[0][node]+dp[1][node]] = [2, 12]
  [node,dp[0][node]+dp[1][node]] = [5, 16]
 */

Compilation message (stderr)

commuter_pass.cpp: In function 'void dij(long long int, long long int*)':
commuter_pass.cpp:62:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   62 |         auto [dis,v]=pq.top();
      |              ^
commuter_pass.cpp: In function 'void setIO(std::string)':
commuter_pass.cpp:40:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   40 |     freopen((s + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
commuter_pass.cpp:41:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   41 |     freopen((s + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 16 / 16
• Subtask 2: 15 / 15
• Subtask 3: 24 / 24
• Subtask 4: 45 / 45