Cod sursa(job #1342611)

Utilizator dianaa21Diana Pislaru dianaa21 Data 14 februarie 2015 11:57:23
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.25 kb
#include <fstream>
#define nmax 100000
using namespace std;
ifstream is ("arbint.in");
ofstream os ("arbint.out");

#define mid (left+right)/2

int Arb[4*nmax];
int N, M, x, y, t, ANSW, L, R;

void Read();
void Update(int,int,int);
void Query(int,int,int);

int main()
{
    Read();
    for(int i = 1; i <= M; ++i)
    {
        is >> t >> y >> x;
        if(t == 0)
        {
            ANSW = 0;
            L = y;
            R = x;
            Query(1, 1, N);
            os << ANSW << "\n";
        }
        else Update(1, 1, N);
    }
    is.close();
    os.close();
    return 0;
}
void Read()
{
    is >> N >> M;
    for(int i = 1; i <= N; ++i)
    {
        is >> x;
        y = i;
        Update(1, 1, N);
    }
}
void Update(int node, int left, int right)
{
    if(left == right)
    {
        Arb[node] = x;
        return;
    }
    if(y <= mid) Update(2*node, left, mid);
    else Update(2*node+1, mid+1, right);

    Arb[node] = max(Arb[2*node], Arb[2*node+1]);
}
void Query(int node ,int left, int right)
{
    if(left >= L && right <= R)
    {
        ANSW = max(ANSW, Arb[node]);
        return;
    }
    if(mid >= L) Query(2*node, left, mid);
    if(mid < R) Query(2*node+1, mid+1, right);
}