Cod sursa(job #1646299)

Utilizator xtreme77Patrick Sava xtreme77 Data 10 martie 2016 15:41:13
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.51 kb
#include <fstream>

using namespace std;

ifstream cin ( "arbint.in" ) ;
ofstream cout ( "arbint.out" ) ;

const int MAX = 1e5 + 14 ;

int arb [ MAX * 4 ] ;

void update ( int nod , int st , int dr , int pos , int val )
{
    if ( st == dr ) {
        arb [ nod ] = val ;
        return ;
    }
    int mij = ( st + dr ) >> 1 ;
    if ( pos <= mij ) {
        update ( nod * 2 , st , mij , pos , val ) ;
    }
    else {
        update ( nod * 2 + 1 , mij + 1 , dr , pos , val ) ;
    }
    arb [ nod ] = max ( arb [ nod * 2 ] , arb [ nod * 2 + 1 ] ) ;
}

int Q ( int nod , int st , int dr , int a , int b )
{
    if ( a <= st and dr <= b )
        return arb [ nod ] ;
    int mij = ( st + dr ) / 2 ;
    int global = 0 ;
    if ( a <= mij ) {
        global = max ( global , Q ( nod * 2 , st , mij , a , b ) ) ;
    }
    if ( b > mij ) {
        global = max ( global , Q ( nod * 2 + 1 , mij + 1 , dr , a , b ) ) ;
    }
    return global ;
}

int main()
{
    int n , m ;
    cin >> n >> m ;
    for ( int i = 1 ; i <= n ; ++ i )
    {
        int x ;
        cin >> x ;
        update ( 1 , 1 , n , i , x ) ;
    }
    while ( m -- )
    {
        int tip ;
        cin >> tip ;
        if ( tip == 0 ) {
            int a , b ;
            cin >> a >> b ;
            cout << Q ( 1 , 1 , n , a , b ) << '\n' ;
        }
        else {
            int pos , val ;
            cin >> pos >> val ;
            update ( 1 , 1 , n , pos , val ) ;
        }
    }
    return 0;
}