Submission #1075648

#	Time	Username	Problem	Language	Result	Execution time	Memory
1075648		Trumling	Dreaming (IOI13_dreaming)	C++14	100 / 100	85 ms	20108 KiB

dreaming

#include "dreaming.h"
#include <bits/stdc++.h>
using namespace std; 
 
typedef long long ll;
#define pb push_back
#define F first
#define S second
#define enter cout<<'\n';
#define INF 99999999999999999
#define MOD 1000000007
#define all(x) x.begin(),x.end()
 
vector<vector<pair<ll,ll>>>g;
vector<bool>vis;
vector<ll>dist,par;
 
ll n,m;
void dfs1(int start,int pre,ll &maxi)
{
    for(auto x:g[start])
        if(x.F!=pre)
        {
            par[x.F]=start;
            vis[x.F]=1;
            dist[x.F]= dist[start] + x.S;
            if(dist[maxi]<dist[x.F])
                maxi=x.F;
 
            dfs1(x.F, start,maxi);
        }
}
 
void dfs2(int start,int pre,ll &ans,ll diff,ll curr,ll count)
{
   
 
    for(auto x:g[start])
        if(x.F!=pre)
            dfs2(x.F,start,ans,diff,curr + x.S,count);
        
}   
int travelTime(int N, int M, int L, int A[], int B[], int T[]) {
    n=N;
    m=M;
 
    g.assign(n,vector<pair<ll,ll>>());
    vis.assign(n,0);
    dist.assign(n,0);
    par.assign(n,0);
    for(int i=0;i<m;i++)
        {
            g[A[i]].pb({B[i],T[i]});
            g[B[i]].pb({A[i],T[i]});
        }
    
    vector<ll>ans;
	ll ansi=-1;
    ll idx=0;
    for(int i=0;i<N;i++)
        if(!vis[i])
        {
            vis[i]=1;
            ll p1=i,p2;
            dfs1(i,i,p1);
            dist[p1]=0;
            p2=p1;
            dfs1(p1,p1,p2);
 
            ll curr=0;
            ll diff=INF;
            ll count=dist[p2];
 
            ansi=max(ansi,dist[p2]);
			ll curri=0;
            while(p2!=p1)
            {
 
            if(diff > abs((count-curr)-curr))
            {
                curri=max(curr,count-curr);
                diff= abs((count-curr)-curr);
            }

            curr+=dist[p2]-dist[par[p2]];
            p2=par[p2];
            }
			ans.pb(curri);
        }
	sort(all(ans));
    return max(ansi,max((((ans.size()>=2))?ans[ans.size()-1] + ans[ans.size()-2] + L:0),((ans.size()>=3)?ans[ans.size()-2] + ans[ans.size()-3] + 2*L:0)));
 
}

Compilation message (stderr)

dreaming.cpp: In function 'int travelTime(int, int, int, int*, int*, int*)':
dreaming.cpp:60:5: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   60 |     for(int i=0;i<N;i++)
      |     ^~~
dreaming.cpp:90:2: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
   90 |  sort(all(ans));
      |  ^~~~
dreaming.cpp:59:8: warning: unused variable 'idx' [-Wunused-variable]
   59 |     ll idx=0;
      |        ^~~

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