Submission #426918

#	Time	Username	Problem	Language	Result	Execution time	Memory
426918		AmineWeslati	Dreaming (IOI13_dreaming)	C++14	14 / 100	1066 ms	14980 KiB

dreaming

#include "dreaming.h"
#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef vector<int>vi; 
#define pb push_back
#define sz(v) (int)v.size()

typedef pair<int,int>pi;
#define fi first
#define se second
typedef vector<pi>vpi;
#define eb emplace_back

#define FOR(i,a,b) for(int i=a; i<b; i++)
#define ROF(i,a,b) for(int i=b-1; i>=a; i--)


void ckmax(int &x, int y){x=max(x,y);}
void ckmin(int &x, int y){x=min(x,y);}

const int MX=1e5+10;
int N,M; 
vpi adj[MX];
vi vis(MX,0);

vi dist(MX);
pi par[MX]; 
void dfs(int u){
    vis[u]=1;
    for(auto it: adj[u]){
        int v=it.fi,w=it.se;
        if(dist[v]==-1){
            dist[v]=dist[u]+w;
            par[v]={u,w};
            dfs(v);
        }
    } 
}

int U,V,diam;

void solve(int u){
    FOR(i,0,N) dist[i]=-1; dist[u]=0; 
    dfs(u);
    int v=u; 
    FOR(i,0,N) if(dist[i]!=-1 && dist[i]>dist[v]) v=i; 

    u=v; 

    FOR(i,0,N) dist[i]=-1; dist[u]=0;
    dfs(u);
    v=u; 
    FOR(i,0,N) if(dist[i]!=-1 && dist[i]>dist[v]) v=i; 

    diam=dist[v];
    tie(U,V)={u,v};
}

int travelTime(int N, int M, int L, int A[], int B[], int T[]) {
    ::N=N; ::M=M; 
    FOR(i,0,M){
        int u=A[i],v=B[i],w=T[i];
        adj[u].eb(v,w);
        adj[v].eb(u,w);
    }

    int ans=0;
    vi vec; 
    FOR(i,0,N) if(!vis[i]){
        solve(i);
        ckmax(ans,diam);
        
        int cur=0,mn=2e9;
        //cout << U << " " << V << endl;
        while(U!=V){
            cur+=par[V].se; 
            V=par[V].fi;

            ckmin(mn,max(diam-cur,cur));
        }
        vec.pb(mn);
    }
    ckmax(ans,vec[0]+vec[1]+L);
    return ans; 
}

/*
12
8
2
0 8 2 5 5 1 1 10
8 2 7 11 1 3 9 6
4 2 4 3 7 1 5 3

*/

/*
12
10
5
0 0 0 1 1 3 7 7 5 5 
1 2 3 4 5 6 8 9 10 11
2 3 1 4 1 6 5 5 5 5 

*/

Compilation message (stderr)

dreaming.cpp: In function 'void solve(int)':
dreaming.cpp:16:20: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   16 | #define FOR(i,a,b) for(int i=a; i<b; i++)
      |                    ^~~
dreaming.cpp:45:5: note: in expansion of macro 'FOR'
   45 |     FOR(i,0,N) dist[i]=-1; dist[u]=0;
      |     ^~~
dreaming.cpp:45:28: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
   45 |     FOR(i,0,N) dist[i]=-1; dist[u]=0;
      |                            ^~~~
dreaming.cpp:16:20: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   16 | #define FOR(i,a,b) for(int i=a; i<b; i++)
      |                    ^~~
dreaming.cpp:52:5: note: in expansion of macro 'FOR'
   52 |     FOR(i,0,N) dist[i]=-1; dist[u]=0;
      |     ^~~
dreaming.cpp:52:28: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
   52 |     FOR(i,0,N) dist[i]=-1; dist[u]=0;
      |                            ^~~~

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