Submission #910911

#TimeUsernameProblemLanguageResultExecution timeMemory
910911asdasdqwerPipes (CEOI15_pipes)C++14
100 / 100
790 ms14732 KiB
#pragma GCC optimize("Os") #include <bits/stdc++.h> using namespace std; #define MAXN 100000 int p1[MAXN], r1[MAXN], p2[MAXN], r2[MAXN]; int lft[MAXN][18]; vector<int> g[MAXN]; int get1(int i) { if (p1[i]!=i && p1[i]!=p1[p1[i]]) p1[i]=get1(p1[i]); return p1[i]; } inline bool unite1(int a,int b) { a=get1(a),b=get1(b); if (a==b)return false; if (r1[a]<r1[b])swap(a,b); p1[b]=a; if (r1[a]==r1[b])r1[a]++; return true; } int get2(int i) { if (p2[i]!=i && p2[i]!=p2[p2[i]]) p2[i]=get2(p2[i]); return p2[i]; } inline bool unite2(int a,int b) { a=get2(a),b=get2(b); if (a==b)return false; if (r2[a]<r2[b])swap(a,b); p2[b]=a; if (r2[a]==r2[b])r2[a]++; return true; } bitset<100000> vis; int main() { ios::sync_with_stdio(false); cin.tie(0); cout.tie(0); int n,m;cin>>n>>m; for (int i=0;i<n;i++) { p1[i]=i; p2[i]=i; } int a,b; for (int i=0;i<m;i++) { cin>>a>>b;a--;b--; if (unite1(a,b)) { g[a].push_back(b); g[b].push_back(a); } else { unite2(a,b); } } for (int i=0;i<n;i++) { r1[i]=0;p1[i]=-1; } // r1.assign(n,0); // p1.assign(n,-1); for (int i=0;i<n;i++) { for (int j=0;j<18;j++) { lft[i][j]=-1; } } // lft.assign(n, vector<int>(18,-1)); for (int i=0;i<n;i++) { if (vis[i]) continue; int pt=0; p1[pt]=i; vis[i]=true; while (pt != -1) { int r=p1[pt--]; for (int x:g[r]) { if (!vis[x]) { vis[x]=true; lft[x][0]=r; r1[x]=r1[r]+1; p1[++pt]=x; } } } } for (int j=1;j<18;j++) { for (int i=0;i<n;i++) { lft[i][j]=lft[i][j-1]; if (lft[i][j] != -1) { lft[i][j]=lft[lft[i][j]][j-1]; } } } for (int i=0;i<n;i++) { r2[i]=0; } int steps; for (int i=0;i<n;i++) { if (p2[i] == i) continue; a=i, b=get2(i); r2[a]++; r2[b]++; if (r1[a]<r1[b])swap(a,b); steps=r1[a]-r1[b]; for (int j=0;j<18;j++) { if ((steps & (1<<j))) { a=lft[a][j]; } } if (a==b) { r2[a]-=2; continue; } for (int j=17;j>-1;--j) { if (lft[a][j] != lft[b][j]) { a=lft[a][j]; b=lft[b][j]; } } r2[lft[a][0]] -= 2; } // for (int i=0;i<n;i++) { // lft[i]={lft[i][0]}; // } for (int i=0;i<n;i++) vis[i]=0; for (int i=0;i<n;i++) { p1[i]=-1; } for (int i=0;i<n;i++) { if (vis[i])continue; int pt=0; vis[i]=true; p1[0]=i; while (pt != -1) { int r=p1[pt]; if (g[r].size()==0) { if (lft[r][0] != -1) { r2[lft[r][0]] += r2[r]; } pt--; continue; } for (int x:g[r]) { if (!vis[x]) { p1[++pt]=x; vis[x]=true; } } g[r].clear(); } } for (int i=0;i<n;i++) { if (r2[i]==0 && lft[i][0] != -1) { cout<<i+1<<" "<<lft[i][0]+1<<"\n"; } } return 0; }
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...