Cod sursa(job #2573174)

Utilizator vmnechitaNechita Vlad-Mihai vmnechita Data 5 martie 2020 16:15:52
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.73 kb
#include <bits/stdc++.h>
#define NMAX 100005

using namespace std;

ifstream fin ("arbint.in");
ofstream fout ("arbint.out");

int v[NMAX], a[2*NMAX];

void construieste ( int nod, int st, int dr );
int intrebare ( int nod, int st, int dr, int x, int y );
void update ( int nod, int st, int dr, int poz, int val );

int main()
{
    int n, q, i, c, x, y;

    fin >> n >> q;
    for ( i = 1 ; i <= n ; i++ ) fin >> v[i];
    construieste ( 1, 1, n );

    while ( q-- )
    {
        fin >> c >> x >> y;
        if ( c == 0 ) fout << intrebare ( 1, 1, n, x, y ) << '\n';
        else update ( 1, 1, n, x, y );
    }

    return 0;
}

void construieste ( int nod, int st, int dr )
{
    int mij;

    if ( st == dr ) a[nod] = v[st];
    else
    {
        mij = ( st + dr ) / 2;
        construieste ( 2 * nod, st, mij );
        construieste ( 2 * nod + 1, mij + 1, dr );
        a[nod] = max ( a[2*nod], a[2*nod+1] );
    }
}

int intrebare ( int nod, int st, int dr, int x, int y )
{
    int mij;

    if ( x <= st && y >= dr ) return a[nod];
    else
    {
        mij = ( st + dr ) / 2;
        if ( y <= mij ) return intrebare ( 2 * nod, st, mij, x, y );
        else if ( x > mij ) return intrebare ( 2 * nod + 1, mij + 1, dr, x, y );
        else return max ( intrebare ( 2 * nod, st, mij, x, y ), intrebare ( 2 * nod + 1, mij + 1, dr, x, y ) );
    }
}

void update ( int nod, int st, int dr, int poz, int val )
{
    int mij;

    if ( st == dr ) a[nod] = val;
    else
    {
        mij = ( st + dr ) / 2;
        if ( poz <= mij ) update ( 2 * nod, st, mij, poz, val );
        else update ( 2 * nod + 1, mij + 1, dr, poz, val );
        a[nod] = max ( a[2*nod], a[2*nod+1] );
    }
}