Submission #420035

#	Time	Username	Problem	Language	Result	Execution time	Memory
420035		Ozy	Dreaming (IOI13_dreaming)	C++17	14 / 100	79 ms	24132 KiB

dreaming

#include "dreaming.h"
#include <bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for (int i = (a); i <= (b); i++)
#define repa(i,a,b) for (int i = (a); i >= (b); i--)
#define lli long long int
#define debugsl(a) cout << #a << " = " << a << ", "
#define debug(a) cout << #a << " = " << a << endl

#define des first
#define val second

lli act,res;
lli visitados[100002],MIN[2];
vector<pair<lli,lli> > hijos[100002],caminos[100002];

lli DSF(lli pos, lli padre) {
    lli tiem = 0;
    lli a = 0;
    lli k = 0;

    visitados[pos] = 1;
    for (auto h : hijos[pos]) {
        if (h.des == padre) {tiem = h.val;continue;}
        a = DSF(h.des,pos);
        caminos[pos].push_back({h.des,a});
        if (a > k) k = a;
    }

    return a + tiem;
}

void optimo(lli pos, lli padre, lli suma) {
    lli dd,prim = 0;
    lli a,seg = 0;

    for (auto h : caminos[pos]) {
        if (h.val > prim){
            seg = prim;
            prim = h.val;
            dd = h.des;
        }
        else if (h.val > seg) seg = h.val;
    }

    a = max(prim,suma);
    if (a < MIN[act]) MIN[act] = a;
    a = prim + seg;
    if (a > res) res = a;

    for (auto h : hijos[pos]) {
        if (h.des == padre) continue;

        if (h.des == dd) optimo(h.des,pos,(max(suma,seg)+h.val));
        else optimo(h.des,pos,(max(suma,prim)+h.val));
    }
}

void procesa(lli pos) {

    lli a = DSF(pos,0);
    optimo(pos,0,0);

}

int travelTime(int N, int M, int L, int A[], int B[], int T[]) {

    rep(i,0,M-1) {
        hijos[A[i]].push_back({B[i],T[i]});
        hijos[B[i]].push_back({A[i],T[i]});
    }

    act = 0;
    res = 0;
    MIN[0] = 1ll<<62;
    MIN[1] = 1ll<<62;

    rep(i,1,N) {
        if (act == 2) break;

        if (visitados[i] == 0) {
            procesa(i);
            act++;
        }
    }

    act = MIN[0] + MIN[1] + L;
    res = max(res,act);
    return res;
}

Compilation message (stderr)

dreaming.cpp: In function 'void procesa(long long int)':
dreaming.cpp:61:9: warning: unused variable 'a' [-Wunused-variable]
   61 |     lli a = DSF(pos,0);
      |         ^
dreaming.cpp: In function 'void optimo(long long int, long long int, long long int)':
dreaming.cpp:54:9: warning: 'dd' may be used uninitialized in this function [-Wmaybe-uninitialized]
   54 |         if (h.des == dd) optimo(h.des,pos,(max(suma,seg)+h.val));
      |         ^~

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