Submission #876548

#	Time	Username	Problem	Language	Result	Execution time	Memory
876548		LucaIlie	Passport (JOI23_passport)	C++17	48 / 100	2093 ms	370372 KiB

passport

#include <bits/stdc++.h>

using namespace std;

const int MAX_N = 2e5 + 10;
const int INF = 1e9;
int l[MAX_N + 1], r[MAX_N + 1], minL[MAX_N + 1], maxR[MAX_N + 1], minSufL[MAX_N + 1], maxPrefR[MAX_N + 1], dist1[MAX_N + 1], distN[MAX_N + 1], dist1R[MAX_N + 1], distNR[MAX_N + 1];

int n;

struct AINT {
    struct px {
        int p, x;

        bool operator < ( const px &a ) const {
            if ( x == a.x )
                return p < a.p;
            return x < a.x;
        }
    };
    set<px> aint[4 * MAX_N];

    void insert( int v, int l, int r, int p, int x, int y ) {
        if ( l > x || r < x )
            return;

        aint[v].insert( { p, y } );
        if ( l == r )
            return;
        int mid = (l + r) / 2;
        insert( v * 2 + 1, l, mid, p, x, y );
        insert( v * 2 + 2, mid + 1, r, p, x, y );
    }

    void erase( int v, int l, int r, int p, int x, int y ) {
        if ( l > x || r < x )
            return;

        aint[v].erase( { p, y } );
        if ( l == r )
            return;
        int mid = (l + r) / 2;
        erase( v * 2 + 1, l, mid, p, x, y );
        erase( v * 2 + 2, mid + 1, r, p, x, y );
    }

    px query( int v, int l, int r, int lq, int rq ) {
        if ( l > rq || r < lq || aint[v].empty() )
            return { 0, 0 };

        if ( lq <= l && r <= rq )
            return *aint[v].rbegin();

        int mid = (l + r) / 2;
        return max( query( v * 2 + 1, l, mid, lq, rq ), query( v * 2 + 2, mid + 1, r, lq, rq ) );
    }
} aint1, aintN;

void calc_dist1() {
    struct dr {
        int i, dist, maxR;

        bool operator < ( const dr &x ) const {
            if ( dist == x.dist )
                return maxR < x.maxR;
            return dist > x.dist;
        }
    };
    for ( int i = 0; i <= n; i++ )
        dist1[i] = INF, maxR[i] = 0;

    priority_queue<dr> pq;
    dist1[1] = 0;
    maxR[1] = 0;
    pq.push( { 1, dist1[1], maxR[1] } );
    while ( !pq.empty() ) {
        auto crt = pq.top();
        pq.pop();

        int i = crt.i;

        if ( crt.dist != dist1[i] || crt.maxR != maxR[i] )
            continue;

        auto a = aint1.query( 0, 1, n, 1, i );
        while ( a.x >= i ) {
            int j = a.p;
            if ( dist1[i] + 1 <= dist1[j] && max( maxR[i], r[j] ) > maxR[j] ) {
                dist1[j] = dist1[i] + 1;
                maxR[j] = max( maxR[i], r[j] );
                pq.push( { j, dist1[j], maxR[j] } );
            }
            aint1.erase( 0, 1, n, j, l[j], r[j] );
            a = aint1.query( 0, 1, n, 1, i );
        }
    }
    dist1[1] = 1;
    maxR[1] = r[1];
}

void calc_distN() {
    struct dr {
        int i, dist, minL;

        bool operator < ( const dr &x ) const {
            if ( dist == x.dist )
                return minL > x.minL;
            return dist > x.dist;
        }
    };
    for ( int i = 0; i <= n; i++ )
        distN[i] = INF, minL[i] = n + 1;

    priority_queue<dr> pq;
    distN[n] = 0;
    minL[n] = n + 1;
    pq.push( { n, distN[n], minL[n] } );
    while ( !pq.empty() ) {
        auto crt = pq.top();
        pq.pop();

        int i = crt.i;
        if ( crt.dist != distN[i] || crt.minL != minL[i] )
            continue;

        auto a = aintN.query( 0, 1, n, 1, i );
        while ( a.x >= i ) {
            int j = a.p;
            if ( distN[i] + 1 <= distN[j] && min( minL[i], l[j] ) < minL[j] ) {
                distN[j] = distN[i] + 1;
                minL[j] = min( minL[i], l[j] );
                pq.push( { j, distN[j], minL[j] } );
            }
            aintN.erase( 0, 1, n, j, l[j], r[j] );
            a = aintN.query( 0, 1, n, 1, i );
        }
    }
    distN[n] = 1;
    minL[n] = r[n];
}

void calc_dist1_rest() {
    for ( int i = 0; i <= n; i++ )
        dist1R[i] = INF;
    minSufL[n] = l[n];
    for ( int i = n - 1; i >= 1; i-- )
        minSufL[i] = min( minSufL[i + 1], l[i] );
    dist1R[1] = 0;
    for ( int i = 2; i <= n; i++ )
        dist1R[i] = dist1R[minSufL[i]] + 1;
}

void calc_distN_rest() {
    for ( int i = n - 1; i >= 0; i-- )
        distNR[i] = INF;
    for ( int i = 1; i <= n; i++ )
        maxPrefR[i] = max( maxPrefR[i - 1], r[i] );
    distNR[n] = 0;
    for ( int i = n - 1; i >= 1; i-- )
        distNR[i] = distNR[maxPrefR[i]] + 1;
}

int main() {
    ios_base::sync_with_stdio( false );
    cin.tie( NULL );
    cout.tie( NULL );

    int q;

    cin >> n;
    for ( int i = 1; i <= n; i++ ) {
        cin >> l[i] >> r[i];
        aint1.insert( 0, 1, n, i, l[i], r[i] );
        aintN.insert( 0, 1, n, i, l[i], r[i] );
    }

    if ( n <= 2500 ) {
         calc_dist1();
         calc_distN();
         calc_dist1_rest();
         calc_distN_rest();
    }
   
    cin >> q;
    while ( q-- ) {
        int x;
        cin >> x;
        int ans = min( distN[x] + dist1R[minL[x]], dist1[x] + distNR[maxR[x]] );
        cout << (ans > n ? -1 : ans) << "\n";
    }

    return 0;
}

• Subtask 1: 0 / 6
• Subtask 2: 16 / 16
• Subtask 3: 24 / 24
• Subtask 4: 8 / 8
• Subtask 5: 0 / 46