Cod sursa(job #3141582)

Utilizator elisa.ipateElisa Ipate elisa.ipate Data 14 iulie 2023 17:38:52
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.44 kb
#include <fstream>
#include <iostream>

#define MAXN 100000

using namespace std;

int v[MAXN], aint[4*MAXN];
int ans;

void init( int nod, int l, int r ) {
    if( r == l )
        aint[nod] = v[r];
    else {
        init( nod*2+1, l, (l+r)/2 );
        init( nod*2+2, (l+r)/2+1, r );
        aint[nod] = max( aint[nod*2+1], aint[nod*2+2] );
    }

}

void update( int nod, int l, int r, int poz, int val ) {
    if( l <= poz && poz <= r ) {
        if( r == l )
            aint[nod] = v[r];
        else {
            update( nod*2+1, l, (l+r)/2, poz, val );
            update( nod*2+2, (l+r)/2+1, r, poz, val );
            aint[nod] = max( aint[nod*2+1], aint[nod*2+2] );
        }
    }
}

void query( int nod, int l, int r, int lq, int rq ) {
    if( lq <= l && rq >= r )
        ans = max( ans, aint[nod] );
    else if( rq < l || lq > r )
        return;
    else{
        query( nod*2+1, l, (l+r)/2, lq, rq );
        query( nod*2+2, (l+r)/2+1, r, lq, rq );
    }

}
int main() {
    int m, n, i, a, b, t;
    ifstream cin( "arbint.in" );
    ofstream cout( "arbint.out" );
    cin >> n >> m;
    for( i = 0; i < n; i++ )
        cin >> v[i];
    init( 0, 0, n-1 );
    for( i = 0; i < m; i++ ) {
        cin >> t >> a >> b;
        if( t == 1 ) {
            v[a-1] = b;
            update( 0, 0, n-1, a-1, b );
        } else {
            ans = 0;
            query( 0, 0, n-1, a-1, b-1 );
            cout << ans << "\n";
        }
    }
    return 0;
}