Cod sursa(job #1488078)

Utilizator tudormaximTudor Maxim tudormaxim Data 17 septembrie 2015 21:24:58
Problema Arbori de intervale Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.19 kb
#include <fstream>
using namespace std;
const int nmax = 100005;
int n, m, arb[3*nmax], maxx;

void update(int nod, int st, int dr, int poz, int val)
{
    if(st>=dr)
    {
        arb[nod]=val;
        return;
    }
    int m=(st+dr)>>1;
    if(poz<=m) update(nod<<1, st, m, poz, val);
    else update(nod<<1 | 1, m+1, dr, poz, val);
    arb[nod]=max(arb[nod<<1], arb[nod<<1 | 1]);
}

int query(int nod, int st, int dr, int start, int finish)
{
    if(start<=st && dr<=finish) return max(arb[nod], maxx);
    int m=(st+dr)>>1;
    if(start<=m) return query(nod<<1, st, m, start, finish);
    if(finish>m) return query(nod<<1 | 1, m+1, dr, start, finish);
}
int main()
{
    freopen("arbint.in", "r", stdin);
    freopen("arbint.out", "w", stdout);
    int i, x, y, t;
    scanf("%d %d", &n, &m);
    for(i=1; i<=n; i++)
    {
        scanf("%d ", &x);
        update(1, 1, n, i, x);
    }
    while(m--)
    {
        scanf("%d %d %d", &t, &x, &y);
        if(t) update(1, 1, n, x, y);
        else
        {
            maxx=0;
            i=query(1, 1, n, x, y);
            printf("%d\n", i);
        }
    }
    fclose(stdin);
    fclose(stdout);
    return 0;
}