제출 #61254

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
61254		dukati8	꿈 (IOI13_dreaming)	C++14	100 / 100	118 ms	14200 KiB

dreaming

#include "dreaming.h"
#include <bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for(int i=a; i<int(b); i++)
vector<vector<pair<int,int> > > G(100000);
bool flags[3][100000];
int largestdist;
int farthestnode;
vector<int> diameter;
//call from one node, farthestnode would then be node farthest away
void dfs(int node,int currdist,int iter) {
  if (flags[iter][node]) return;
  if (currdist>largestdist) {
    largestdist=currdist;
    farthestnode=node;
  }
  flags[iter][node]=true;
  for (auto x:G[node]) {
    int other=x.first;
    int cost=x.second;
    dfs(other,currdist+cost,iter);
  }
}
bool dfs2(int node, int dest) {
  if (node==dest) {return true;}
  if (flags[2][node]) return false;
  flags[2][node]=true;
  for (auto x:G[node]) {
    if (dfs2(x.first,dest)) {diameter.push_back(x.second); return true;}
  }
  return false;
}
int travelTime(int N, int M, int L, int A[], int B[], int T[]) {
    //For each connected component, find radius and diameter
    vector<int> diameters;
    vector<int> radiuses;
    rep(i,0,M) {
      int a,b;
      a=A[i];
      b=B[i];
      int c=T[i];
      G[a].push_back(make_pair(b,c));
      G[b].push_back(make_pair(a,c));
    }
    rep (i,0,N) {
      if (flags[0][i]) continue;
      //New subgraph
      largestdist=-1;
      farthestnode=-1;
      dfs(i,0,0);
      int a,b;
      a=farthestnode;
      largestdist=-1;
      farthestnode=-1;
      dfs(a,0,1);
      b=farthestnode;
      diameter.clear();
      dfs2(a,b);
      diameters.push_back(largestdist);
      //Now just find centroid
      int count=0;
      int radius=largestdist;
      for (auto x:diameter) {
        count+=x;
        radius=min(radius,max(count,largestdist-count));
      }
      assert(count==largestdist);
      radiuses.push_back(radius);
    }
    int ans=diameters[0];
    for (auto x:diameters) {
      ans=max(ans,x);
    }
    sort(radiuses.begin(),radiuses.end());
    int numradius=radiuses.size();
    if (numradius>=2) {
      ans=max(ans,radiuses[numradius-1]+radiuses[numradius-2]+L);

    }
    if (numradius>=3) {
      ans=max(ans,radiuses[numradius-2]+radiuses[numradius-3]+2*L);
    }
    return ans;
}

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