Submission #945609

#	Time	Username	Problem	Language	Result	Execution time	Memory
945609		yeediot	Valley (BOI19_valley)	C++14	0 / 100	108 ms	48884 KiB

valley

#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())
#define __lg(x) 63-__builtin_clzll(x)
#define pow2(x) (1LL<<x)
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];
bool isshop[mxn];
int dep[mxn],d[mxn];
int in[mxn],out[mxn];
int timer;
vector<tuple<int,int,int>>edge;
int jump[20][mxn],mn[20][mxn];
int ord[mxn];
int dp[mxn];
int pre[mxn];
void dfs(int v,int pa){
    in[v]=++timer;
    ord[timer]=v;
    jump[0][v]=pa;
    if(isshop[v])dp[v]=0;
    else dp[v]=1e18;
    for(auto [u,pp]:adj[v]){
        if(u==pa)continue;
        dep[u]=dep[v]+pp;
        d[u]=d[v]+1;
        dfs(u,v);
        dp[v]=min(dp[v],dp[u]+pp);
    }
    out[v]=timer;
}
int lca(int v,int u){
    if(dep[v]<dep[u])swap(v,u);
    int dif=d[v]-d[u];
    for(int i=0;i<20;i++){
        if(dif>>i&1){
            v=jump[i][v];
        }
    }
    if(v==u)return v;
    for(int i=19;i>=0;i--){
        if(jump[i][v]!=jump[i][u]){
            v=jump[i][v];
            u=jump[i][u];
        }
    }
    return jump[0][v];
}
int ans[mxn];
void calc(int v,int pa){
    mn[0][v]=dp[jump[0][v]]-dep[jump[0][v]];
    for(auto [u,dd]:adj[v]){
        if(u==pa)continue;
        calc(u,v);
    }
}
signed main(){
    setio();
    ios::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    int n,s,q,e;
    cin>>n>>s>>q>>e;
    for(int i=1;i<n;i++){
        int a,b,c;
        cin>>a>>b>>c;
        adj[a].pb({b,c});
        adj[b].pb({a,c});
        edge.pb({a,b,c});
    }
    for(int i=1;i<=s;i++){
        int x;
        cin>>x;
        isshop[x]=1;
    }
    dfs(e,e);
    for(int i=1;i<20;i++){
        for(int j=1;j<=n;j++){
            jump[i][j]=jump[i-1][jump[i-1][j]];
        }
    }
    calc(e,e);
    for(int i=1;i<=n;i++){
        debug(mn[0][i],jump[0][i],dp[i],dep[i]);
    }
    for(int i=1;i<20;i++){
        for(int j=1;j<=n;j++){
            mn[i][j]=min(mn[i-1][j],mn[i-1][jump[i-1][j]]);
        }
    }
    while(q--){
        int id,v;
        cin>>id>>v;
        id--;
        auto [x,y,l]=edge[id];
        if(d[x]<d[y])swap(x,y);
        debug(x);
        if(in[x]<=in[v] and in[v]<=out[x]){
            int an=dp[v]+dep[v];
            int cur=v;
            for(int i=19;i>=0;i--){
                if(dep[jump[i][cur]]>=dep[x]){
                    an=min(an,mn[i][cur]+dep[v]);
                    cur=jump[i][cur];
                    debug(cur);
                }
            }
            if(an>=1e18){
                cout<<"oo\n";
            }
            else{
                cout<<an<<'\n';
            }
        }  
        else{
            cout<<"escaped\n";
        }
    }
}
 /*
 input:
 
 */















 

Compilation message (stderr)

valley.cpp: In function 'void dfs(long long int, long long int)':
valley.cpp:71:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   71 |     for(auto [u,pp]:adj[v]){
      |              ^
valley.cpp: In function 'void calc(long long int, long long int)':
valley.cpp:100:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  100 |     for(auto [u,dd]:adj[v]){
      |              ^
valley.cpp: In function 'int main()':
valley.cpp:142:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  142 |         auto [x,y,l]=edge[id];
      |              ^
valley.cpp: In function 'void setIO(std::string)':
valley.cpp:42:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   42 |     freopen((s + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
valley.cpp:43:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   43 |     freopen((s + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 9
• Subtask 2: 0 / 27
• Subtask 3: 0 / 23
• Subtask 4: 0 / 41