Submission #1197611

#	Time	Username	Problem	Language	Result	Execution time	Memory
1197611		Malix	Swapping Cities (APIO20_swap)	C++20	100 / 100	501 ms	81616 KiB

swap

#include "swap.h"
#include <bits/stdc++.h>
using namespace std;
 
typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vii;
typedef pair<int,int> pi;
typedef vector<pi> pii;
typedef tuple<int,int,int> ti;
typedef vector<ll> li;
typedef vector<li> lii;
 
#define REP(i,a,b) for(int i=a;i<b;i++)
#define F first
#define S second
#define PB push_back
#define LSOne(s) ((s)&(-s))

ll INF=1000000000000000010;
int inf=1e9+10;
ll M=1e9+7;

int n,k,v1=1,v2=1,pos;
vii p,X,q;
vector<vector<pi>> a;
vi low,num,par,sw,cnt,d,Y;
bool flag=0;

void dfs(int x){
  num[x]=v1++;
  for(auto u:a[x])if(p[x][0]!=u.F){
    p[u.F][0]=x;
    X[u.F][0]=u.S;
    dfs(u.F);
  }
  low[x]=v2++;
}

int parent(int x){
  if(par[x]==x)return x;
  else return par[x]=parent(par[x]);
}

bool merge(int x,int y,int w){
  int xt=x,yt=y;
  x=parent(x);
  y=parent(y);
  if(x==y){
    par[x]=pos;
    sw[pos]=1;
    q[x][0]=pos;
    Y[pos]=w;
    pos++;
    return 0;
  }
  par[x]=pos;par[y]=pos;
  cnt[xt]++;cnt[yt]++;
  q[x][0]=pos;q[y][0]=pos;
  Y[pos]=w;
  if(cnt[xt]>=3||cnt[yt]>=3||sw[x]||sw[y])sw[pos]=1;
  pos++;
  return 1;
}

void init(int N, int M,std::vector<int> U, std::vector<int> V, std::vector<int> W) {
  n=N;
  k=log2(n+M)+1;
  low.resize(n,0);num.resize(n,0);
  p.resize(n,vi(k,-1));
  X.resize(n,vi(k,0));
  a.resize(n);
  sw.resize(N+M,0);d.resize(n+M,0);
  par.resize(N+M);q.resize(N+M,vi(k,-1));Y.resize(N+M,inf);
  REP(i,0,N+M)par[i]=i;
  cnt.resize(n,0);
  priority_queue<ti,vector<ti>,greater<ti>> pq;
  REP(i,0,M)pq.push({W[i],U[i],V[i]});
  pos=n;
  while(!pq.empty()){
    int x=get<0>(pq.top());
    int y=get<1>(pq.top());
    int z=get<2>(pq.top());
    pq.pop();
    if(merge(y,z,x)){
      a[y].PB({z,x});
      a[z].PB({y,x});
    }
  }
  dfs(0);
  REP(j,1,k)REP(i,0,n)if(p[i][j-1]!=-1){
    p[i][j]=p[p[i][j-1]][j-1];
    X[i][j]=max(X[i][j-1],X[p[i][j-1]][j-1]);
  }
  REP(j,1,k)REP(i,0,n+M)if(q[i][j-1]!=-1)q[i][j]=q[q[i][j-1]][j-1];
  if(sw[n+M-1]==0)flag=1;
  for(int i=n+M-2;i>=0;i--)d[i]=d[q[i][0]]+1;
}

bool ances(int x,int y){
  if(y==-1)return 1;
  if(x==-1)return 0;
  return (num[y]<=num[x]&&low[y]>=low[x]);
}

int solve(int x,int y){
  if(d[x]<d[y])swap(x,y);
  for(int i=k-1;i>=0;i--)if(q[x][i]!=-1&&d[q[x][i]]>=d[y])x=q[x][i];
  for(int i=k-1;i>=0;i--)if(q[x][i]!=q[y][i]){
    x=q[x][i];
    y=q[y][i];
  }
  x=q[x][0];
  y=q[y][0];
  if(sw[x])return Y[x];
  for(int i=k-1;i>=0;i--)if(q[x][i]!=-1&&sw[q[x][i]]==0)x=q[x][i];
  x=q[x][0];
  return Y[x];
}

int getMinimumFuelCapacity(int x, int y) {
  if(flag)return -1;
  int ans=0,ans2=solve(x,y);
  for(int i=k-1;i>=0;i--)if(!ances(y,p[x][i])){
    ans=max(ans,X[x][i]);
    x=p[x][i];
  }
  for(int i=k-1;i>=0;i--)if(!ances(x,p[y][i])){
    ans=max(ans,X[y][i]);
    y=p[y][i];
  }
  if(ances(y,x))swap(x,y);
  ans=max(ans,X[x][0]);
  if(!ances(x,y))ans=max(ans,X[y][0]);
  return max(ans,ans2);
}

• Subtask 1: 6 / 6
• Subtask 2: 7 / 7
• Subtask 3: 17 / 17
• Subtask 4: 20 / 20
• Subtask 5: 23 / 23
• Subtask 6: 27 / 27