Submission #306007

#	Time	Username	Problem	Language	Result	Execution time	Memory
306007		juggernaut	Dreaming (IOI13_dreaming)	C++14	0 / 100	1093 ms	12024 KiB

dreaming

#include"dreaming.h"
//#include"grader.c"
#include<bits/stdc++.h>
#define fr first
#define sc second
using namespace std;
vector<pair<int,int>>g[100005];
bool vis[100005];
int mx[100005],mx2[100005],id[100005],mm,idd;
int dfs(int v,int p){
    vis[v]=1;
    int i=0,x;
  	id[v]=-1;
    for(;i<g[v].size();i++)
        if(g[v][i].fr!=p){
            x=dfs(g[v][i].fr,v)+g[v][i].sc;
            if(x>mx2[v]){
                mx2[v]=x;
                id[v]=g[v][i].fr;
            }
        }
    return mx2[v];
}
void go(int v,int p,int val,int depth){
    mx[v]=max(val,depth);
    int m=0,i=0;
    for(;i<g[v].size();i++)
        if(g[v][i].fr!=p)
        if(g[v][i].fr!=id[v]){
            m=max(m,mx2[g[v][i].fr]+g[v][i].sc);
            go(g[v][i].fr,v,max(mx2[v],val)+g[v][i].sc,depth+g[v][i].sc);
        }
    if(id[v]!=-1)go(id[v],v,max(m,val)+g[v][i].sc,depth+g[v][i].sc);
}
void calc(int v,int p){
    if(max(mx2[v],mx[v])<mm){
        mm=max(mx2[v],mx[v]);
        idd=v;
    }
    for(auto to:g[v])if(to.fr!=p)calc(to.fr,v);
}
void diam(int v,int p,int depth){
    if(depth>mm){
        mm=depth;
        idd=v;
    }
    for(auto to:g[v])if(to.fr!=p)diam(to.fr,v,depth+to.sc);
}
int travelTime(int n,int m,int l,int x[],int y[],int z[]){
    for(int i=0;i<m;i++){
        g[x[i]].push_back({y[i],z[i]});
        g[y[i]].push_back({x[i],z[i]});
    }
    priority_queue<pair<int,int>>st;
    g[n].push_back({n,0});
    for(int i=0;i<n;i++)if(!vis[i]){
        g[n][0].fr=i;
        dfs(n,n);
        go(n,n,0,0);
        mm=2e9;
        calc(n,n);
        st.push({mm,idd});
    }
    g[n].clear();
    auto a=st.top();
    st.pop();
    while(!st.empty()){
        auto b=st.top();
        st.pop();
        g[a.sc].push_back({b.sc,l});
        g[b.sc].push_back({a.sc,l});
    }
    mm=0;
    diam(0,0,0);
    mm=0;
    diam(idd,idd,0);
    return mm;
}

Compilation message (stderr)

dreaming.cpp: In function 'int dfs(int, int)':
dreaming.cpp:14:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   14 |     for(;i<g[v].size();i++)
      |          ~^~~~~~~~~~~~
dreaming.cpp: In function 'void go(int, int, int, int)':
dreaming.cpp:27:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   27 |     for(;i<g[v].size();i++)
      |          ~^~~~~~~~~~~~

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