Cod sursa(job #214402)

Utilizator RobybrasovRobert Hangu Robybrasov Data 14 octombrie 2008 09:33:18
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.27 kb
// Arbore de intervale

#include <stdio.h>

int n,i,j,A[300000],poz,elem,st,dr,mmax,m,nr,a,b;

inline int max(int a, int b)
{
    return (a>b)?a:b;
}

void update(int nod, int a, int b)
{
    if (a==b) A[nod]=elem;
    else
    {
        int m=(a+b)/2;
        if (poz<=m) update(nod*2,a,m);
        else        update(nod*2+1,m+1,b);
        A[nod]=max(A[nod*2],A[nod*2+1]);
    }
}

void query(int nod, int a, int b)
{
    if (st<=a && dr>=b) mmax=max(mmax,A[nod]);
    else
    {
        int m=(a+b)/2;
        if (st<=m) query(nod*2,a,m);
        if (dr>m)  query(nod*2+1,m+1,b);
    }
}

int main()
{
    freopen("arbint.in","r",stdin);
    freopen("arbint.out","w",stdout);
    scanf("%d %d\n",&n,&m);
    /*
    se construieste arborele, care initial contine 0,
    prin adaugarea succesiva de elemente.
    */
    for (i=1; i<=n; i++)
    {
        scanf("%d",&elem);
        poz=i;
        update(1,1,n);
    }
    for (i=1; i<=m; i++)
    {
        scanf("%d %d %d\n",&nr,&a,&b);
        if (nr)
        {
            poz=a; elem=b;
            update(1,1,n);
        }
        else
        {
            st=a; dr=b;
            mmax=0;
            query(1,1,n);
            printf("%d\n",mmax);
        }
    }
    return 0;
}