oj.uz

Submission #522057

# Submission time Handle Problem Language Result Execution time Memory
522057 2022-02-03T16:48:24 Z DanerZein Aesthetic (NOI20_aesthetic) C++14
20 / 100
 566 ms 38076 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=dis[n-1]+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;
	  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];
	    res=min(res,d1[x]+dis[y]+1);
	  }
	}
      }
      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 1 ms 564 KB Output is correct
2 Correct 2 ms 588 KB Output is correct
3 Correct 1 ms 588 KB Output is correct
4 Correct 2 ms 588 KB Output is correct
5 Correct 2 ms 588 KB Output is correct
6 Correct 2 ms 588 KB Output is correct
7 Correct 2 ms 588 KB Output is correct
8 Correct 1 ms 588 KB Output is correct

Subtask #2
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 564 KB Output is correct
2 Correct 2 ms 588 KB Output is correct
3 Correct 1 ms 588 KB Output is correct
4 Correct 2 ms 588 KB Output is correct
5 Correct 2 ms 588 KB Output is correct
6 Correct 2 ms 588 KB Output is correct
7 Correct 2 ms 588 KB Output is correct
8 Correct 1 ms 588 KB Output is correct
9 Correct 362 ms 796 KB Output is correct
10 Correct 363 ms 792 KB Output is correct
11 Correct 252 ms 792 KB Output is correct
12 Correct 246 ms 792 KB Output is correct
13 Correct 192 ms 756 KB Output is correct
14 Correct 180 ms 768 KB Output is correct
15 Correct 169 ms 752 KB Output is correct
16 Correct 172 ms 756 KB Output is correct

Subtask #3
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 512 ms 28544 KB Output is correct
2 Correct 505 ms 28568 KB Output is correct
3 Correct 492 ms 28224 KB Output is correct
4 Correct 488 ms 28180 KB Output is correct
5 Correct 498 ms 28416 KB Output is correct
6 Correct 493 ms 28924 KB Output is correct
7 Correct 491 ms 28812 KB Output is correct
8 Correct 505 ms 28988 KB Output is correct

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Incorrect 566 ms 32160 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #5
0 / 16.0

# Verdict Execution time Memory Grader output
1 Incorrect 562 ms 38076 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #6
0 / 22.0

# Verdict Execution time Memory Grader output
1 Incorrect 562 ms 38076 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #7
0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 564 KB Output is correct
2 Correct 2 ms 588 KB Output is correct
3 Correct 1 ms 588 KB Output is correct
4 Correct 2 ms 588 KB Output is correct
5 Correct 2 ms 588 KB Output is correct
6 Correct 2 ms 588 KB Output is correct
7 Correct 2 ms 588 KB Output is correct
8 Correct 1 ms 588 KB Output is correct
9 Correct 362 ms 796 KB Output is correct
10 Correct 363 ms 792 KB Output is correct
11 Correct 252 ms 792 KB Output is correct
12 Correct 246 ms 792 KB Output is correct
13 Correct 192 ms 756 KB Output is correct
14 Correct 180 ms 768 KB Output is correct
15 Correct 169 ms 752 KB Output is correct
16 Correct 172 ms 756 KB Output is correct
17 Correct 512 ms 28544 KB Output is correct
18 Correct 505 ms 28568 KB Output is correct
19 Correct 492 ms 28224 KB Output is correct
20 Correct 488 ms 28180 KB Output is correct
21 Correct 498 ms 28416 KB Output is correct
22 Correct 493 ms 28924 KB Output is correct
23 Correct 491 ms 28812 KB Output is correct
24 Correct 505 ms 28988 KB Output is correct
25 Incorrect 566 ms 32160 KB Output isn't correct
26 Halted 0 ms 0 KB -