Submission #229898

#	Time	Username	Problem	Language	Result	Execution time	Memory
229898		caoash	Dreaming (IOI13_dreaming)	C++14	18 / 100	78 ms	18552 KiB

dreaming

#pragma GCC target ("sse4")

#include <bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
#include "dreaming.h"

using namespace std;
using namespace __gnu_pbds;
 
typedef long long ll;
typedef long double ld;
typedef complex<ld> cd;

typedef pair<int, int> pi;
typedef pair<ll,ll> pl;
typedef pair<ld,ld> pd;
typedef pair<int, pi> pii;

typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<cd> vcd;

#define fax(i, a) for (int i = 0; i < (a); i++)
#define f0x(i, a, b) for (int i = (a); i < (b); i++)
#define f0xd(i,a,b) for (int i = (b)-1; i >= (a); i--)
#define faxd(i,a) for (int i = (a)-1; i >= 0; i--)
#define trav(a, x) for (auto& a : x)
#define memeset memset

#define mp make_pair
#define pb push_back
#define f first
#define s second
#define lb lower_bound
#define ub upper_bound

#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define rsz resize

template<class T> void ckmin(T &a, T b) { a = min(a, b); }
template<class T> void ckmax(T &a, T b) { a = max(a, b); }

template <class T, int ...Ns> struct BIT {
    T val = 0;
    void upd(T v) { val += v; }
    T query() { return val; }
};
 
template <class T, int N, int... Ns> struct BIT<T, N, Ns...> {
    BIT<T,Ns...> bit[N + 1];
    template<typename... Args> void upd(int pos, Args... args) {
        for (; pos <= N; pos += (pos&-pos)) bit[pos].upd(args...);
    }
    template<typename... Args> T sum(int r, Args... args) {
        T res = 0; for (; r; r -= (r&-r)) res += bit[r].query(args...); 
        return res;
    }
    template<typename... Args> T query(int l, int r, Args... args) {
        return sum(r,args...)-sum(l-1,args...);
    }
};

namespace input {
    template<class T> void re(complex<T>& x);
    template<class T1, class T2> void re(pair<T1,T2>& p);
    template<class T> void re(vector<T>& a);
    template<class T, size_t SZ> void re(array<T,SZ>& a);

    template<class T> void re(T& x) { cin >> x; }
    void re(double& x) { string t; re(t); x = stod(t); }
    void re(ld& x) { string t; re(t); x = stold(t); }
    template<class T, class... Ts> void re(T& t, Ts&... ts) { 
        re(t); re(ts...); 
    }

    template<class T> void re(complex<T>& x) { T a,b; re(a,b); x = cd(a,b); }
    template<class T1, class T2> void re(pair<T1,T2>& p) { re(p.f,p.s); }
    template<class T> void re(vector<T>& a) { fax(i,sz(a)) re(a[i]); }
    template<class T, size_t SZ> void re(array<T,SZ>& a) { fax(i,SZ) re(a[i]); }
}

using namespace input;

namespace output {
    void pr(int x) { cout << x; }
    void pr(long x) { cout << x; }
    void pr(ll x) { cout << x; }
    void pr(unsigned x) { cout << x; }
    void pr(unsigned long x) { cout << x; }
    void pr(unsigned long long x) { cout << x; }
    void pr(float x) { cout << x; }
    void pr(double x) { cout << x; }
    void pr(ld x) { cout << x; }
    void pr(char x) { cout << x; }
    void pr(const char* x) { cout << x; }
    void pr(const string& x) { cout << x; }
    void pr(bool x) { pr(x ? "true" : "false"); }
    
    template<class T1, class T2> void pr(const pair<T1,T2>& x);
    template<class T> void pr(const T& x);
    
    template<class T, class... Ts> void pr(const T& t, const Ts&... ts) { 
        pr(t); pr(ts...); 
    }
    template<class T1, class T2> void pr(const pair<T1,T2>& x) { 
        pr("{",x.f,", ",x.s,"}"); 
    }
    template<class T> void pr(const T& x) { 
        pr("{"); // const iterator needed for vector<bool>
        bool fst = 1; for (const auto& a: x) pr(!fst?", ":"",a), fst = 0; 
        pr("}");
    }
    
    void ps() { pr("\n"); } // print w/ spaces
    template<class T, class... Ts> void ps(const T& t, const Ts&... ts) { 
        pr(t); if (sizeof...(ts)) pr(" "); ps(ts...); 
    }
    
    void pc() { pr("]\n"); } // debug w/ commas
    template<class T, class... Ts> void pc(const T& t, const Ts&... ts) { 
        pr(t); if (sizeof...(ts)) pr(", "); pc(ts...); 
    }
    #define dbg(x...) pr("[",#x,"] = ["), pc(x);
}

using namespace output;

namespace io {
    void setIn(string s) { freopen(s.c_str(),"r",stdin); }
    void setOut(string s) { freopen(s.c_str(),"w",stdout); }
    void setIO(string s = "") {
        ios_base::sync_with_stdio(0); cin.tie(0); // fast I/O
        if (sz(s)) { setIn(s+".in"), setOut(s+".out"); } // for USACO
    }
}

using namespace io;

mt19937 rnd(chrono::high_resolution_clock::now().time_since_epoch().count());

const int MOD = 1000000007; // 998244353
const ll INF = 1e18;
const int MX = 200005;
const ld PI = 4*atan((ld)1);

vpi adj[MX]; int dp1[MX], dp2[MX], ans[MX], val[MX];

void dfs1(int v, int p){
   for(pi to : adj[v]){
      if(to.f != p){
         dfs1(to.f, v);
         dp1[v] = max(dp1[v], dp1[to.f]+to.s);
         val[to.f] = to.s;
      }
   }
}

void dfs2(int v, int p){
   if(p != -1){
      dp2[v] = max(dp2[v], dp2[p]+val[v]);
   }
   for(pi to2 : adj[p]){
      if(to2.f != v){
         dp2[v] = max(dp2[v], dp1[to2.f] + val[v] + to2.s);
      }
   }
   for(pi to : adj[v]){
      if(to.f != p){
        dfs2(to.f, v);
      }
   }
}
bool vis[MX];
pi dfs_ans(int v, int p){
   vis[v] = true;
   pi ret = mp(max(dp1[v], dp2[v]), v);
   for(pi to : adj[v]){
      if(to.f != p){
         pi nxt = dfs_ans(to.f, v);
         ckmin(ret, nxt);
      }
   }
   return ret;
}

pi dfs(int v, int p, int d){
   pi best = mp(d,v);
   for(pi to : adj[v]){
     if(to.f != p){ 
        ckmax(best, dfs(to.f, v, d+to.s)); 
     }
   }
   return best;
}

int diam(int v, int p){
   pi far = dfs(0,-1, 0);
   return dfs(far.s, -1, 0).f;
}

int travelTime(int N, int M, int L, int a[], int b[], int c[]){
  fax(i,M){
   //dbg(a[i], b[i], c[i]);
   adj[a[i]].pb(mp(b[i],c[i]));
   adj[b[i]].pb(mp(a[i],c[i]));
  }
  vpi roots;
  fax(i,N){
   if(!vis[i]){
     dfs1(i,-1); dfs2(i,-1); 
     pi fin = dfs_ans(i,-1);
     roots.pb(mp(fin.f, fin.s));
   }
  }
  sort(all(roots));
  //dbg(roots);
  fax(i,sz(roots)-1){
   int u = roots[sz(roots)-1].s; int v = roots[i].s; int w = L;
   //dbg(u,v,w);
   adj[u].pb(mp(v,w));
   adj[v].pb(mp(u,w));
  }
  return diam(0,-1);
}

Compilation message (stderr)

dreaming.cpp: In function 'void io::setIn(std::__cxx11::string)':
dreaming.cpp:134:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
     void setIn(string s) { freopen(s.c_str(),"r",stdin); }
                            ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
dreaming.cpp: In function 'void io::setOut(std::__cxx11::string)':
dreaming.cpp:135:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
     void setOut(string s) { freopen(s.c_str(),"w",stdout); }
                             ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 14
• Subtask 2: 0 / 10
• Subtask 3: 0 / 23
• Subtask 4: 18 / 18
• Subtask 5: 0 / 12
• Subtask 6: 0 / 23