oj.uz

Submission #522131

# Submission time Handle Problem Language Result Execution time Memory
522131 2022-02-03T22:55:02 Z DanerZein Aesthetic (NOI20_aesthetic) C++14
20 / 100
 591 ms 41796 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;
	  if(bri[id]) 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 2 ms 556 KB Output is correct
2 Correct 2 ms 544 KB Output is correct
3 Correct 1 ms 588 KB Output is correct
4 Correct 2 ms 560 KB Output is correct
5 Correct 2 ms 564 KB Output is correct
6 Correct 1 ms 588 KB Output is correct
7 Correct 1 ms 560 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 556 KB Output is correct
2 Correct 2 ms 544 KB Output is correct
3 Correct 1 ms 588 KB Output is correct
4 Correct 2 ms 560 KB Output is correct
5 Correct 2 ms 564 KB Output is correct
6 Correct 1 ms 588 KB Output is correct
7 Correct 1 ms 560 KB Output is correct
8 Correct 2 ms 588 KB Output is correct
9 Correct 356 ms 800 KB Output is correct
10 Correct 363 ms 792 KB Output is correct
11 Correct 245 ms 792 KB Output is correct
12 Correct 257 ms 796 KB Output is correct
13 Correct 165 ms 716 KB Output is correct
14 Correct 175 ms 716 KB Output is correct
15 Correct 166 ms 752 KB Output is correct
16 Correct 169 ms 844 KB Output is correct

Subtask #3
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 504 ms 32300 KB Output is correct
2 Correct 487 ms 32388 KB Output is correct
3 Correct 520 ms 32044 KB Output is correct
4 Correct 507 ms 32012 KB Output is correct
5 Correct 498 ms 32168 KB Output is correct
6 Correct 514 ms 32708 KB Output is correct
7 Correct 520 ms 32700 KB Output is correct
8 Correct 540 ms 32776 KB Output is correct

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Incorrect 591 ms 35952 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #5
0 / 16.0

# Verdict Execution time Memory Grader output
1 Incorrect 563 ms 41796 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #6
0 / 22.0

# Verdict Execution time Memory Grader output
1 Incorrect 563 ms 41796 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 556 KB Output is correct
2 Correct 2 ms 544 KB Output is correct
3 Correct 1 ms 588 KB Output is correct
4 Correct 2 ms 560 KB Output is correct
5 Correct 2 ms 564 KB Output is correct
6 Correct 1 ms 588 KB Output is correct
7 Correct 1 ms 560 KB Output is correct
8 Correct 2 ms 588 KB Output is correct
9 Correct 356 ms 800 KB Output is correct
10 Correct 363 ms 792 KB Output is correct
11 Correct 245 ms 792 KB Output is correct
12 Correct 257 ms 796 KB Output is correct
13 Correct 165 ms 716 KB Output is correct
14 Correct 175 ms 716 KB Output is correct
15 Correct 166 ms 752 KB Output is correct
16 Correct 169 ms 844 KB Output is correct
17 Correct 504 ms 32300 KB Output is correct
18 Correct 487 ms 32388 KB Output is correct
19 Correct 520 ms 32044 KB Output is correct
20 Correct 507 ms 32012 KB Output is correct
21 Correct 498 ms 32168 KB Output is correct
22 Correct 514 ms 32708 KB Output is correct
23 Correct 520 ms 32700 KB Output is correct
24 Correct 540 ms 32776 KB Output is correct
25 Incorrect 591 ms 35952 KB Output isn't correct
26 Halted 0 ms 0 KB -