Submission #955214

#	Time	Username	Problem	Language	Result	Execution time	Memory
955214		amine_aroua	Railway Trip 2 (JOI22_ho_t4)	C++17	16 / 100	2044 ms	16748 KiB

Main

#include <bits/stdc++.h>
//#pragma GCC optimize("O3")
//#pragma GCC optimize("unroll-loops")
using namespace std;
#define int long long
#define vi vector<int>
#define vl vector<long long>
#define vii vector<pair<int,int>>
#define vll vector<pair<long long,long long>>
#define pb push_back
#define ll long long
#define ld long double
#define nl '\n'
#define boost ios::sync_with_stdio(false)
#define mp make_pair
#define se second
#define fi first
#define fore(i, y) for(int i = 0; i < y; i++)
#define forr(i,x,y) for(int i = x;i<=y;i++)
#define forn(i,y,x) for(int i = y; i >= x; i--)
#define all(v) v.begin(),v.end()
#define sz(v) (int)v.size()
#define clr(v,k) memset(v,k,sizeof(v))
#define rall(v) v.rbegin() , v.rend()
#define pii pair<int,int>
#define pll pair<ll , ll>

const ll MOD = 1e9 + 7;
const ll INF = 1e18 + 1;

ll gcd(ll a , ll b) {return b ? gcd(b , a % b) : a ;} // greatest common divisor (gcd)
ll lcm(ll a , ll b) {return a * (b / gcd(a , b));} // least common multiple (lcm)

// HERE IS THE SOLUTION
vi mxTree , mnTree;
int n;
void build()
{
    while(__builtin_popcount(n) != 1)
        n++;
    mxTree.assign(2*n , 0);
    mnTree.assign(2*n , n + 1);
}
void upd(int node , int L , int R , int l , int  r , int x , bool type)
{
    if(l <= L && R <= r)
    {
        if(!type)
            mxTree[node] = max(mxTree[node] , x);
        else
            mnTree[node] = min(mnTree[node] , x);
        return ;
    }
    if(l > R || L > r)
        return ;
    int mid = (L + R)/2;
    upd(2*node , L , mid , l , r , x ,  type);
    upd(2*node + 1 , mid + 1 , R , l , r , x , type);
}
int getMax(int i)
{
    int ans = i;
    for(int j = (i + n); j>= 1;j/=2)
    {
        ans = max(ans , mxTree[j]);
    }
    return ans;
}
int getMin(int i)
{
    int ans = i;
    for(int j = (i + n); j>= 1;j/=2)
    {
        ans = min(ans , mnTree[j]);
    }
    return ans;
}

signed main()
{
    boost;
    cin.tie(0);
    cout.tie(0);
    int N , K , M;
    cin>>N>>K>>M;
    n = N +1;
    build();
    vector<vi> adj(N + 1);
    forr(i , 1  , N)
    {
        adj[i] = {i , i};
    }
    fore(i , M)
    {
        int A , B;
        cin>>A>>B;
        if(A < B)
        {
            upd(1 , 0 , n - 1 , A , min(B - 1 , A + K - 1) , B , 0);
        }
        else
        {
            upd(1 , 0 , n - 1 , max(B + 1 , A - K + 1) , A , B , 1);
        }
    }
    forr(i , 1 , N)
    {
        adj[i][0] = getMin(i);
        adj[i][1] = getMax(i);
    }
    if(K == 1)
    {
        int Q;
        cin>>Q;
        while(Q--)
        {
            int S , T;
            cin>>S>>T;
            queue<int> q;
            q.push(S);
            vi dist(N + 1 , INF);
            vector<bool> vis(N + 1 , 0);
            dist[S] = 0;
            while(!q.empty())
            {
                int cur = q.front();
                q.pop();
                if(vis[cur])
                    continue;
                vis[cur] = 1;
                if(cur == T)
                    break;
                int mn = INF , mx = -INF;
                int mnL , mxR;
                for(int u = adj[cur][0] ; u <= adj[cur][1]; u++)
                {
                    if(dist[u] > dist[cur] + 1)
                        dist[u] = dist[cur] + 1;
                    if(adj[u][0] < mn)
                    {
                        mn = adj[u][0];
                        mnL = u;
                    }
                    if(adj[u][1] > mx)
                    {
                        mx = adj[u][1];
                        mxR = u;
                    }
                }
                q.push(mnL);
                q.push(mxR);
            }
            cout<<(dist[T] == INF ? -1 : dist[T])<<nl;
        }
    }
    else
    {
        int Q;
        cin>>Q;
        while(Q--)
        {
            int S , T;
            cin>>S>>T;
            queue<int> q;
            q.push(S);
            vi dist(N + 1 , INF);
            set<int> free;
            forr(i , 1 , N)
                free.insert(i);
            dist[S] = 0;
            while(!q.empty())
            {
                int cur = q.front();
                q.pop();
                if(!free.count(cur))
                    continue;
                if(cur == T)
                    break;
                int mn = INF , mx = -INF;
                int mnL = -1, mxR = -1;
                auto it1 = free.lower_bound(adj[cur][0]);
                auto it2 = free.upper_bound(adj[cur][1]);
                for(auto it = it1 ; it!= it2; it++)
                {
                    int u = *it;
                    if(dist[u] > dist[cur] + 1)
                        dist[u] = dist[cur] + 1;
                    if(adj[u][0] < mn)
                    {
                        mn = adj[u][0];
                        mnL = u;
                    }
                    if(adj[u][1] > mx)
                    {
                        mx = adj[u][1];
                        mxR = u;
                    }
                }
                vector<int> to_erase;
                for(auto it = it1 ; it!= it2; it++)
                {
                    int u = *it;
                    if(u == mnL || u == mxR)
                        continue;
                    to_erase.pb(u);
                }
                for(auto it : to_erase)
                    free.erase(it);
                if(mnL != -1)
                    q.push(mnL);
                if(mxR != -1)
                    q.push(mxR);
                free.erase(cur);
            }
            cout<<(dist[T] >= INF ? -1 : dist[T])<<nl;
        }
    }

}

• Subtask 1: 8 / 8
• Subtask 2: 8 / 8
• Subtask 3: 0 / 11
• Subtask 4: 0 / 25
• Subtask 5: 0 / 35
• Subtask 6: 0 / 13