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Submission #522133

# Submission time Handle Problem Language Result Execution time Memory
522133 2022-02-03T23:11:51 Z DanerZein Aesthetic (NOI20_aesthetic) C++14
20 / 100
 528 ms 28824 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;
int otro(int id,int x){
  if(a[id]==x) return b[id];
  else return a[id];
}
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){
      if(!sw){
	for(int i=0;i<path.size();i++){
	  if(path[i].second!=m-1)
	    bri[path[i].second]=1;
	}
        int u=n-1;
	while(u!=0){
	  ll mi=MAX;
	  int id=-1;
	  for(auto &v:G[u]){
	    if(!bri[v]){
	      int y=otro(v,u);
	      if(mi>dis[y]){
		mi=dis[y];
		id=y;
	      }
	    }
	  }
	  if(id==-1) break;
	  u=id;
	}
	res=dis[n-1];
	if(u!=0) res++;
	
      }
      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:47:9: warning: unused variable 'k' [-Wunused-variable]
   47 |     int k=pq.top().first;
      |         ^
Aesthetic.cpp: In function 'int main()':
Aesthetic.cpp:107:18: 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]
  107 |     for(int i=0;i<path.size();i++){
      |                 ~^~~~~~~~~~~~
Aesthetic.cpp:117:15: 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]
  117 |  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 2 ms 588 KB Output is correct
4 Correct 1 ms 588 KB Output is correct
5 Correct 2 ms 556 KB Output is correct
6 Correct 2 ms 588 KB Output is correct
7 Correct 1 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 2 ms 588 KB Output is correct
4 Correct 1 ms 588 KB Output is correct
5 Correct 2 ms 556 KB Output is correct
6 Correct 2 ms 588 KB Output is correct
7 Correct 1 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 374 ms 756 KB Output is correct
11 Correct 241 ms 716 KB Output is correct
12 Correct 255 ms 716 KB Output is correct
13 Correct 169 ms 736 KB Output is correct
14 Correct 174 ms 716 KB Output is correct
15 Correct 183 ms 724 KB Output is correct
16 Correct 166 ms 720 KB Output is correct

Subtask #3
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 510 ms 28192 KB Output is correct
2 Correct 526 ms 28336 KB Output is correct
3 Correct 517 ms 27968 KB Output is correct
4 Correct 494 ms 27976 KB Output is correct
5 Correct 515 ms 28036 KB Output is correct
6 Correct 503 ms 28664 KB Output is correct
7 Correct 528 ms 28612 KB Output is correct
8 Correct 512 ms 28824 KB Output is correct

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Incorrect 521 ms 28764 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #5
0 / 16.0

# Verdict Execution time Memory Grader output
1 Incorrect 406 ms 25512 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #6
0 / 22.0

# Verdict Execution time Memory Grader output
1 Incorrect 406 ms 25512 KB Output isn't correct
2 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 2 ms 588 KB Output is correct
4 Correct 1 ms 588 KB Output is correct
5 Correct 2 ms 556 KB Output is correct
6 Correct 2 ms 588 KB Output is correct
7 Correct 1 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 374 ms 756 KB Output is correct
11 Correct 241 ms 716 KB Output is correct
12 Correct 255 ms 716 KB Output is correct
13 Correct 169 ms 736 KB Output is correct
14 Correct 174 ms 716 KB Output is correct
15 Correct 183 ms 724 KB Output is correct
16 Correct 166 ms 720 KB Output is correct
17 Correct 510 ms 28192 KB Output is correct
18 Correct 526 ms 28336 KB Output is correct
19 Correct 517 ms 27968 KB Output is correct
20 Correct 494 ms 27976 KB Output is correct
21 Correct 515 ms 28036 KB Output is correct
22 Correct 503 ms 28664 KB Output is correct
23 Correct 528 ms 28612 KB Output is correct
24 Correct 512 ms 28824 KB Output is correct
25 Incorrect 521 ms 28764 KB Output isn't correct
26 Halted 0 ms 0 KB -