Cod sursa(job #1542224)

Utilizator vlady1997Vlad Bucur vlady1997 Data 5 decembrie 2015 10:13:54
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.22 kb
#include <cstdio>
#include <algorithm>
using namespace std;
int a[400001], Max;
void update (int val, int poz, int nod, int p, int r)
{
    int m=(p+r)/2;
    if (p==poz && r==poz)
    {
        a[nod]=val;
        while (nod>0)
        {
            nod/=2;
            a[nod]=max(a[nod*2],a[nod*2+1]);
        }
        return;
    }
    if (m>=poz)
    {
        update(val,poz,nod*2,p,m);
    }
    else
    {
        update(val,poz,nod*2+1,m+1,r);
    }
}
void query (int x, int y, int nod, int p, int r)
{
    int m=(p+r)/2;
    if (p>=x && r<=y)
    {
        Max=max(Max,a[nod]);
        return;
    }
    if (m>=x) query(x,y,nod*2,p,m);
    if (m<y) query(x,y,nod*2+1,m+1,r);
}
int main()
{
    int n, m, i, p, x, y;
    freopen("arbint.in","r",stdin);
    freopen("arbint.out","w",stdout);
    scanf("%d%d",&n,&m);
    for (i=1; i<=n; i++)
    {
        scanf("%d",&x);
        update(x,i,1,1,n);
    }
    for (i=1; i<=m; i++)
    {
        scanf("%d%d%d",&p,&x,&y);
        if (p==0)
        {
            Max=0;
            query(x,y,1,1,n);
            printf("%d\n",Max);
        }
        else
        {
            update(y,x,1,1,n);
        }
    }
    return 0;
}