oj.uz

Submission #522132

# Submission time Handle Problem Language Result Execution time Memory
522132 2022-02-03T23:02:02 Z DanerZein Aesthetic (NOI20_aesthetic) C++14
20 / 100
 628 ms 37764 KB 
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll,int> ii;
typedef vector<int> vi;
const int MAX_N=3e5+10;
const ll MAX=1e15;
ll ma[MAX_N];
ll dis[MAX_N];
vector<vi> G;
vector<ll> a,b,w;
int n,m;
bool pri[MAX_N];
bool bri[MAX_N],vis[MAX_N];
int num[MAX_N],low[MAX_N];
int it=0;
void bridge(int u,int p){
  num[u]=low[u]=it++;
  vis[u]=1;
  for(auto &v:G[u]){
    int y;
    if(u==a[v]) y=b[v];
    else y=a[v];
    if(!vis[y]){
      bridge(y,u);
      if(low[y]>num[u]){
	bri[v]=1;
      }
      low[u]=min(low[u],low[y]);
    }
    else
      if(y!=p)
	low[u]=min(low[u],num[v]);
  }
}
vector<ii> bfs(int u){
  for(int i=0;i<n;i++) dis[i]=MAX;
  dis[u]=0;
  priority_queue<ii, vector<ii>, greater<ii> > pq;
  pq.push(ii(0,u));
  while(!pq.empty()){
    int x=pq.top().second;
    int k=pq.top().first;
    pq.pop();
    for(auto &v:G[x]){
      int y;
      if(x==a[v]) y=b[v];
      else y=a[v];
      if(dis[y]>dis[x]+w[v]){
	dis[y]=dis[x]+w[v];
	pq.push(ii(dis[y],y));
      }
    }
  }
  memset(pri,0,sizeof pri);
  vector<ii> path;
  int st,en;
  if(u==0){
    en=0; st=n-1;
  }
  else{
    st=0; en=n-1;
  }
  u=st;
  while(u!=en){
    int id=-1;
    ll mi=MAX;
    for(auto &v:G[u]){
      int y;
      if(u==a[v]) y=b[v];
      else y=a[v];
      if(mi>dis[y]){
	id=v; mi=dis[y];
      }
    }
    if(u==a[id]) u=b[id];
    else u=a[id];
    path.push_back(ii(u,id));
  }
  reverse(path.begin(),path.end());
  return path;
}
int main(){
  cin>>n>>m;
  G.resize(n+1);
  bool sw=0;
  for(int i=0;i<m;i++){
    int x,y,z; cin>>x>>y>>z;
    x--; y--;
    if(z!=1) sw=1;
    a.push_back(x);
    b.push_back(y);
    w.push_back(z);
    G[x].push_back(i);
    G[y].push_back(i);
  }
  ma[m]=0;
  for(int i=m-1;i>=0;i--)
    ma[i]=max(ma[i+1],w[i+1]);
  ll res=0;
  vector<ii> path=bfs(0);
  if(m==n-1){
    for(int i=0;i<path.size();i++){
      int id=path[i].second;
      if(id==m-1) continue;
      ll rp=dis[n-1]+ma[id];
      res=max(res,rp);
    }
  }
  else{
    if(m==n || !sw){
      bridge(0,0);
      if(!sw){
	res=-1;
	vector<ll> d1;
	for(int i=0;i<n;i++) d1.push_back(dis[i]);
	bfs(n-1);
	for(int i=0;i<path.size();i++){
	  int id=path[i].second;
	  if(id==m-1) continue;
	  ll rp=MAX;
	  if(bri[id]){
	    rp=min(rp,d1[n-1]+1);
	  }
	  else{
	    int x=path[i].first;
	    for(auto &v:G[x]){
	      if(id==v) continue;
	      int y;
	      if(x==a[v]) y=b[v];
	      else y=a[v];
	      rp=min(rp,d1[x]+dis[y]);
	    }
	  }
	  res=max(res,rp);
	}
      }
      else{
	
      }
    }
    else{
      for(int i=0;i<m-1;i++){
	w[i]+=ma[i];
	bfs(0);
	res=max(res,dis[n-1]);
	w[i]-=ma[i];
      }
      
    }
  }
  cout<<res<<endl;
}

Compilation message

Aesthetic.cpp: In function 'std::vector<std::pair<long long int, int> > bfs(int)':
Aesthetic.cpp:43:9: warning: unused variable 'k' [-Wunused-variable]
   43 |     int k=pq.top().first;
      |         ^
Aesthetic.cpp: In function 'int main()':
Aesthetic.cpp:103:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  103 |     for(int i=0;i<path.size();i++){
      |                 ~^~~~~~~~~~~~
Aesthetic.cpp:118:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  118 |  for(int i=0;i<path.size();i++){
      |              ~^~~~~~~~~~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 588 KB Output is correct
2 Correct 2 ms 588 KB Output is correct
3 Correct 1 ms 588 KB Output is correct
4 Correct 1 ms 588 KB Output is correct
5 Correct 1 ms 588 KB Output is correct
6 Correct 1 ms 588 KB Output is correct
7 Correct 2 ms 588 KB Output is correct
8 Correct 2 ms 588 KB Output is correct

Subtask #2
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 588 KB Output is correct
2 Correct 2 ms 588 KB Output is correct
3 Correct 1 ms 588 KB Output is correct
4 Correct 1 ms 588 KB Output is correct
5 Correct 1 ms 588 KB Output is correct
6 Correct 1 ms 588 KB Output is correct
7 Correct 2 ms 588 KB Output is correct
8 Correct 2 ms 588 KB Output is correct
9 Correct 348 ms 716 KB Output is correct
10 Correct 367 ms 716 KB Output is correct
11 Correct 291 ms 752 KB Output is correct
12 Correct 244 ms 716 KB Output is correct
13 Correct 175 ms 716 KB Output is correct
14 Correct 182 ms 720 KB Output is correct
15 Correct 172 ms 716 KB Output is correct
16 Correct 171 ms 728 KB Output is correct

Subtask #3
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 542 ms 28136 KB Output is correct
2 Correct 513 ms 28292 KB Output is correct
3 Correct 486 ms 27928 KB Output is correct
4 Correct 565 ms 27952 KB Output is correct
5 Correct 473 ms 28032 KB Output is correct
6 Correct 532 ms 28676 KB Output is correct
7 Correct 503 ms 28616 KB Output is correct
8 Correct 498 ms 28724 KB Output is correct

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Incorrect 628 ms 31876 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #5
0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 559 ms 37764 KB Output is correct
2 Correct 335 ms 37624 KB Output is correct
3 Incorrect 343 ms 31888 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #6
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 559 ms 37764 KB Output is correct
2 Correct 335 ms 37624 KB Output is correct
3 Incorrect 343 ms 31888 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #7
0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 588 KB Output is correct
2 Correct 2 ms 588 KB Output is correct
3 Correct 1 ms 588 KB Output is correct
4 Correct 1 ms 588 KB Output is correct
5 Correct 1 ms 588 KB Output is correct
6 Correct 1 ms 588 KB Output is correct
7 Correct 2 ms 588 KB Output is correct
8 Correct 2 ms 588 KB Output is correct
9 Correct 348 ms 716 KB Output is correct
10 Correct 367 ms 716 KB Output is correct
11 Correct 291 ms 752 KB Output is correct
12 Correct 244 ms 716 KB Output is correct
13 Correct 175 ms 716 KB Output is correct
14 Correct 182 ms 720 KB Output is correct
15 Correct 172 ms 716 KB Output is correct
16 Correct 171 ms 728 KB Output is correct
17 Correct 542 ms 28136 KB Output is correct
18 Correct 513 ms 28292 KB Output is correct
19 Correct 486 ms 27928 KB Output is correct
20 Correct 565 ms 27952 KB Output is correct
21 Correct 473 ms 28032 KB Output is correct
22 Correct 532 ms 28676 KB Output is correct
23 Correct 503 ms 28616 KB Output is correct
24 Correct 498 ms 28724 KB Output is correct
25 Incorrect 628 ms 31876 KB Output isn't correct
26 Halted 0 ms 0 KB -