Cod sursa(job #431948)

Utilizator DranaXumAlexandru Dumitru Paunoiu DranaXum Data 1 aprilie 2010 17:47:15
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.12 kb
#include<iostream>

#define max(a,b) ((a>b)?a:b)
#define NMAX 100001

using namespace std;

int maxa[4*NMAX+100];
int maxv=0;

void update(int n,int l,int r,int i,int v)
{
    if(l==r)
    {    maxa[n]=v; return;}
    int m;
    m=(l+r)/2;
    if(i<=m) update(2*n,l,m,i,v);
    else update(2*n+1,m+1,r,i,v);
    maxa[n]=max(maxa[2*n],maxa[2*n+1]);
}

void query(int n,int l,int r,int s,int d)
{
    if(s<=l && r<=d)
    {
        if(maxv<maxa[n]) maxv=maxa[n];
        return;
    }
    int m;
    m=(l+r)/2;
    if(s<=m) query(2*n,l,m,s,d);
    if(m<d) query(2*n+1,m+1,r,s,d);
}

int main()
{
    freopen("arbint.in","r",stdin);
    freopen("arbint.out","w",stdout);
    int i,n,m;
    int a,b;
    scanf("%d%d",&n,&m);
    for(i=1;i<=n;i++)
    {
        scanf("%d",&a);
        update(1,1,n,i,a);
    }
   for(i=1;i<=m;i++)
    {
        int op;
        scanf("%d%d%d",&op,&a,&b);
        if(op)
        {
            update(1,1,n,a,b);
        }
        else
        {
            maxv=0;
            query(1,1,n,a,b);
            printf("%d\n",maxv);
        }
    }
    return 0;
}