Submission #922837

#	Time	Username	Problem	Language	Result	Execution time	Memory
922837		GrindMachine	Railway Trip 2 (JOI22_ho_t4)	C++17	100 / 100	394 ms	59772 KiB

Main

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) (int)a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x,y) ((x+y-1)/(y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl

#define rep(i,n) for(int i = 0; i < n; ++i)
#define rep1(i,n) for(int i = 1; i <= n; ++i)
#define rev(i,s,e) for(int i = s; i >= e; --i)
#define trav(i,a) for(auto &i : a)

template<typename T>
void amin(T &a, T b) {
    a = min(a,b);
}

template<typename T>
void amax(T &a, T b) {
    a = max(a,b);
}

#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif

/*

refs:
https://codeforces.com/blog/entry/99837?#comment-886479

*/

const int MOD = 1e9 + 7;
const int N = 1e5 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;
const int LOG = 18;

template<typename T>
struct segtree {
    // https://codeforces.com/blog/entry/18051

    /*=======================================================*/

    struct data {
        pii a;
    };

    data neutral = {{inf1,-inf1}};

    data merge(data &left, data &right) {
        data curr;
        curr.a.ff = min(left.a.ff,right.a.ff);
        curr.a.ss = max(left.a.ss,right.a.ss);
        return curr;
    }

    void create(int i, T v) {
        tr[i].a = v;
    }

    void modify(int i, T v) {
        tr[i].a = v;
    }

    /*=======================================================*/

    int n;
    vector<data> tr;

    segtree() {

    }

    segtree(int siz) {
        init(siz);
    }

    void init(int siz) {
        n = siz;
        tr.assign(2 * n, neutral);
    }

    void build(vector<T> &a, int siz) {
        rep(i, siz) create(i + n, a[i]);
        rev(i, n - 1, 1) tr[i] = merge(tr[i << 1], tr[i << 1 | 1]);
    }

    void pupd(int i, T v) {
        modify(i + n, v);
        for (i = (i + n) >> 1; i; i >>= 1) tr[i] = merge(tr[i << 1], tr[i << 1 | 1]);
    }

    data query(int l, int r) {
        data resl = neutral, resr = neutral;

        for (l += n, r += n; l <= r; l >>= 1, r >>= 1) {
            if (l & 1) resl = merge(resl, tr[l++]);
            if (!(r & 1)) resr = merge(tr[r--], resr);
        }

        return merge(resl, resr);
    }
};

void solve(int test_case)
{
    int n,k,m; cin >> n >> k >> m;
    vector<pii> a(m+5);
    rep1(i,m) cin >> a[i].ff >> a[i].ss;

    pii up[n+5][LOG];

    {
        vector<int> enter[n+5], leave[n+5];
        rep1(i,m){
            auto [l,r] = a[i];
            if(l > r) conts;
            amin(r,l+k-1);
            enter[l].pb(a[i].ss);
            leave[r+1].pb(a[i].ss);        
        }

        multiset<int> ms;
        ms.insert(0);

        rep1(i,n){
            trav(r,enter[i]){
                ms.insert(r);
            }
            trav(r,leave[i]){
                ms.erase(ms.find(r));
            }
            up[i][0].ss = max(*ms.rbegin(),i);
        }
    }

    {
        vector<int> enter[n+5], leave[n+5];
        rep1(i,m){
            auto [l,r] = a[i];
            if(l < r) conts;
            amax(r,l-k+1);
            enter[l].pb(a[i].ss);
            leave[r-1].pb(a[i].ss);       
        }

        multiset<int> ms;
        ms.insert(n+1);

        rev(i,n,1){
            trav(r,enter[i]){
                ms.insert(r);
            }
            trav(r,leave[i]){
                ms.erase(ms.find(r));
            }
            up[i][0].ff = min(*ms.begin(),i);
        }
    }

    rep1(j,LOG-1){
        segtree<pii> st(n+5);
        vector<pii> prev_jump(n+5);
        rep1(i,n) prev_jump[i] = up[i][j-1];
        st.build(prev_jump,n+1);

        rep1(i,n){
            up[i][j] = st.query(up[i][j-1].ff,up[i][j-1].ss).a;
        }
    }

    segtree<pii> st[LOG];
    rep(j,LOG){
        st[j] = segtree<pii>(n+5);
        vector<pii> jump(n+5);
        rep1(i,n) jump[i] = up[i][j];
        st[j].build(jump,n+1);
    }

    int q; cin >> q;
    while(q--){
        int s,t; cin >> s >> t;
        if(!(up[s][LOG-1].ff <= t and up[s][LOG-1].ss >= t)){
            cout << -1 << endl;
            conts;
        }
        
        int lx = s, rx = s;
        int ans = 0;

        rev(j,LOG-1,0){
            auto mx_reach = st[j].query(lx,rx).a;
            if(!(mx_reach.ff <= t and mx_reach.ss >= t)){
                ans += 1<<j;
                lx = mx_reach.ff;
                rx = mx_reach.ss;
            }
        }

        ans++;
        cout << ans << endl;
    }
}

int main()
{
    fastio;

    int t = 1;
    // cin >> t;

    rep1(i, t) {
        solve(i);
    }

    return 0;
}

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