oj.uz

답안 #522053

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
522053 2022-02-03T16:28:23 Z DanerZein Aesthetic (NOI20_aesthetic) C++14
20 / 100
 586 ms 35912 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){
	bool r1=0;
	for(int i=0;i<path.size();i++){
	  int id=path[i].second;
	  if(id==m-1) continue;
	  if(bri[id]){
	    r1=1;
	    break;
	  }     
	}
	res=dis[n-1]+r1;
      }
      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:115:15: 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]
  115 |  for(int i=0;i<path.size();i++){
      |              ~^~~~~~~~~~~~

Subtask #1
5.0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 3 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 2 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

# 결과 실행 시간 메모리 Grader output
1 Correct 3 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 2 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 357 ms 776 KB Output is correct
10 Correct 393 ms 716 KB Output is correct
11 Correct 256 ms 752 KB Output is correct
12 Correct 255 ms 748 KB Output is correct
13 Correct 175 ms 720 KB Output is correct
14 Correct 178 ms 728 KB Output is correct
15 Correct 178 ms 836 KB Output is correct
16 Correct 170 ms 716 KB Output is correct

Subtask #3
7.0 / 7.0

# 결과 실행 시간 메모리 Grader output
1 Correct 498 ms 28124 KB Output is correct
2 Correct 525 ms 28292 KB Output is correct
3 Correct 499 ms 28324 KB Output is correct
4 Correct 493 ms 27924 KB Output is correct
5 Correct 488 ms 28344 KB Output is correct
6 Correct 517 ms 28680 KB Output is correct
7 Correct 498 ms 28548 KB Output is correct
8 Correct 515 ms 28916 KB Output is correct

Subtask #4
0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 586 ms 31860 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #5
0 / 16.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 458 ms 35912 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #6
0 / 22.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 458 ms 35912 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #7
0 / 27.0

# 결과 실행 시간 메모리 Grader output
1 Correct 3 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 2 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 357 ms 776 KB Output is correct
10 Correct 393 ms 716 KB Output is correct
11 Correct 256 ms 752 KB Output is correct
12 Correct 255 ms 748 KB Output is correct
13 Correct 175 ms 720 KB Output is correct
14 Correct 178 ms 728 KB Output is correct
15 Correct 178 ms 836 KB Output is correct
16 Correct 170 ms 716 KB Output is correct
17 Correct 498 ms 28124 KB Output is correct
18 Correct 525 ms 28292 KB Output is correct
19 Correct 499 ms 28324 KB Output is correct
20 Correct 493 ms 27924 KB Output is correct
21 Correct 488 ms 28344 KB Output is correct
22 Correct 517 ms 28680 KB Output is correct
23 Correct 498 ms 28548 KB Output is correct
24 Correct 515 ms 28916 KB Output is correct
25 Incorrect 586 ms 31860 KB Output isn't correct
26 Halted 0 ms 0 KB -