Submission #533994

#	Time	Username	Problem	Language	Result	Execution time	Memory
533994		Carmel_Ab1	Evacuation plan (IZhO18_plan)	C++17	100 / 100	1623 ms	90332 KiB

plan

/*
#pragma GCC target ("avx2")
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")
 */
#include<bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>

//using namespace __gnu_pbds;
using namespace std;

typedef long double ld;
typedef long long ll;
typedef unsigned long long ull;
typedef vector<int>vi;
typedef vector<vector<int>>vvi;
typedef vector<ll>vl;
typedef vector<vl> vvl;
typedef pair<int,int>pi;
typedef pair<ll,ll> pl;
typedef vector<pl> vpl;
typedef vector<ld> vld;
typedef pair<ld,ld> pld;
typedef vector<pi> vpi;

//typedef tree<ll, null_type, less_equal<ll>,rb_tree_tag,tree_order_statistics_node_update> ordered_set;
template<typename T> ostream& operator<<(ostream& os, vector<T>& a){os<<"[";for(int i=0; i<ll(a.size()); i++){os << a[i] << ((i!=ll(a.size()-1)?" ":""));}os << "]\n"; return os;}

#define all(x) x.begin(),x.end()
#define YES out("YES")
#define NO out("NO")
#define out(x){cout << x << "\n"; return;}
#define outfl(x){cout << x << endl;return;}
#define GLHF ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL)
#define print(x){for(auto ait:x) cout << ait << " "; cout << "\n";}
#define pb push_back
#define umap unordered_map

template<typename T1, typename T2> istream& operator>>(istream& is, pair<T1, T2>& p){is >> p.first >> p.second;return is;}
template<typename T1, typename T2> ostream& operator<<(ostream& os, pair<T1, T2>& p){os <<"" << p.first << " " << p.second << ""; return os;}
void usaco(string taskname){
    string fin = taskname + ".in";
    string fout = taskname + ".out";
    const char* FIN = fin.c_str();
    const char* FOUT = fout.c_str();
    freopen(FIN, "r", stdin);
    freopen(FOUT, "w", stdout);
}
template<typename T>
void read(vector<T>& v){
    int n=v.size();
    for(int i=0; i<n; i++)
        cin >> v[i];
}
template<typename T>
vector<T>UNQ(vector<T>a){
    vector<T>ans;
    for(T t:a)
        if(ans.empty() || t!=ans.back())
            ans.push_back(t);
    return ans;
}



void solve();
int main(){
    GLHF;
    int t=1;
    //cin >> t;
    while(t--)
        solve();
}
vi par,rnk;
int get(int x){return par[x]=(x==par[x]?x:get(par[x]));}
void unite(int u,int v){
    par[get(u)]=get(v);
}

vector<vpi> build(vvi E,int n){
    int edges=0;
    sort(all(E),greater<vi>());
    par.resize(n+1);
    rnk.resize(n+1,1);

    for(int i=1; i<=n; i++)
        par[i]=i;

    vector<vpi> g(n+1);
    for(vi vv:E){
        int u=vv[1],v=vv[2];
        if(get(u)==get(v))continue;
        unite(u,v);
        edges++;
        int w=vv[0];
        g[u].pb({v,w});
        g[v].pb({u,w});
        if(edges==n-1)break;
    }
    return g;
}

vvi up,mn;
vector<vpi>g;
int lg=18;
vi dep;

void dfs(int x,int p){
    up[x][0]=p;
    if(p!=-1)dep[x]=dep[p]+1;

    for(int j=1; j<lg; j++)
        if(up[x][j-1]!=-1) {
            up[x][j] = up[up[x][j - 1]][j - 1];
            mn[x][j] = min(mn[x][j - 1], mn[up[x][j - 1]][j - 1]);
        }
    for(pi nbr:g[x])
        if(nbr.first!=p){
            mn[nbr.first][0]=nbr.second;
            dfs(nbr.first,x);
        }
}

int lca(int u,int v){
    if(dep[u]>dep[v])swap(u,v);
    for(int i=0; i<lg ;i++)
        if((dep[v]-dep[u])&(1<<i))
            v=up[v][i];

    for(int i=lg-1; 0<=i;i --)
        if(up[u][i]!=up[v][i])
            u=up[u][i],v=up[v][i];
    if(u!=v)u=up[u][0];
    return u;
}

int qur(int x,int k){
    int ans=1e9;
    for(int i=0; i<lg; i++)
        if(k&(1<<i)){
            ans=min(ans,mn[x][i]);
            x=up[x][i];
        }
    return ans;
}

void solve() {
    int n,m;
    cin >> n >> m;
    g.resize(n+1);
    vvi E;
    for(int i=0; i<m; i++){
        int u,v,w;
        cin >> u >> v >> w;
        assert(w<=1000);
        g[u].pb({v,w});
        g[v].pb({u,w});
        E.pb({w,u,v});
    }

    priority_queue<vi,vvi,greater<>>pq;
    int k;
    cin >> k;
    for(int i=0; i<k; i++){
        int x;
        cin >> x;
        pq.push({0,x});
    }

    vector<bool>vis(n+1);
    vi a(n+1);

    while(pq.size()){
        vi v=pq.top();
        pq.pop();
        int x=v[1],w=v[0];
        if(vis[x])continue;
        vis[x]=1;
        a[x]=w;
        for(pi nbr:g[x])
            if(!vis[nbr.first] && w+nbr.second>0)
                pq.push({w+nbr.second,nbr.first});
    }

    for(vi& v:E)
        v[0]=min(a[v[1]],a[v[2]]);
    g=build(E,n);

    up.resize(n+1,vi(lg,-1));
    mn.resize(n+1,vi(lg,-1));
    dep.resize(n+1);

    dfs(1,-1);

    int q;
    cin >> q;

    while(q--){
        int s,t;
        cin >> s >> t;
        int l=lca(s,t);
        int ans=qur(s,dep[s]-dep[l]);
        ans=min(ans,qur(t,dep[t]-dep[l]));
        cout << ans << "\n";
    }

}
/*
 9 12
1 9 4
1 2 5
2 3 7
2 4 3
4 3 6
3 6 4
8 7 10
6 7 5
5 8 1
9 5 7
5 4 12
6 8 2
2
4 7
5
1 6
5 3
4 8
5 8
1 5
 */

Compilation message (stderr)

plan.cpp: In function 'void usaco(std::string)':
plan.cpp:47:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   47 |     freopen(FIN, "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~
plan.cpp:48:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   48 |     freopen(FOUT, "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 13 / 13
• Subtask 3: 12 / 12
• Subtask 4: 19 / 19
• Subtask 5: 46 / 46