제출 #427195

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
427195		AmineWeslati	꿈 (IOI13_dreaming)	C++14	47 / 100	1075 ms	16320 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 u2,v2,m2,c,d;
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; 

    int diam=dist[v];
    tie(u2,v2)={u,v};


    int cur=0,mn=2e9;

    m2=v; c=0; d=0;
    while(u!=v){
        cur+=par[v].se; 
        v=par[v].fi;

        if(max(diam-cur,cur)<mn){
            mn=max(diam-cur,cur); 
            m2=v; c=diam-cur; d=cur; 
        }
    }
}


void find_middle(int u, int v){
    FOR(i,0,N) dist[i]=-1; dist[u]=0;
    dfs(u);
    int diam=dist[v];

    int cur=0,mn=2e9;
    m2=v; c=0; d=0;
    while(u!=v){
        cur+=par[v].se; 
        v=par[v].fi;

        if(max(diam-cur,cur)<mn){
            mn=max(diam-cur,cur); 
            m2=v; c=diam-cur; d=cur; 
        }
    }
}

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 u=-1,v,m,a,b; 
    FOR(i,0,N) if(!vis[i]){
        solve(i);

        //cout << i << endl;
        //cout << u2 << ' ' << v2 << ' ' << m2 << ' ' << c << ' ' << d << endl;
        
        if(u==-1){
            tie(u,v)={u2,v2};
            m=m2;
            tie(a,b)={c,d};  
        }
        else{
            if(c+d>max(a+b, max(a,b)+max(c,d)+L) ){
                tie(u,v)={u2,v2};
                m=m2;
                tie(a,b)={c,d};  
            }
            else if(max(a,b)+max(c,d)+L>max(a+b,c+d)){
                adj[m].eb(m2,L);
                adj[m2].eb(m,L);


                int nu,nv; 
                if(a>=b) nu=u; 
                else nu=v; 

                if(c>=d) nv=u2;
                else nv=v2;

                tie(u,v)={nu,nv};

                //cout << u << ' ' << v << endl;
                //cout << m << ' '<< m2 << endl;
                //cout << endl;

                find_middle(u,v);
                m=m2; a=c; b=d; 

                //cout << m << endl;
            }
        }
    }
    return a+b; 
}

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

18

*/

/*
12
10
5

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

22
*/

컴파일 시 표준 에러 (stderr) 메시지

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;
      |                            ^~~~
dreaming.cpp: In function 'void find_middle(int, 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:77:5: note: in expansion of macro 'FOR'
   77 |     FOR(i,0,N) dist[i]=-1; dist[u]=0;
      |     ^~~
dreaming.cpp:77:28: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
   77 |     FOR(i,0,N) dist[i]=-1; dist[u]=0;
      |                            ^~~~
dreaming.cpp: In function 'int travelTime(int, int, int, int*, int*, int*)':
dreaming.cpp:146:14: warning: 'b' may be used uninitialized in this function [-Wmaybe-uninitialized]
  146 |     return a+b;
      |              ^
dreaming.cpp:146:14: warning: 'a' may be used uninitialized in this function [-Wmaybe-uninitialized]

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