Cod sursa(job #1414405)

Utilizator vasica38Vasile Catana vasica38 Data 2 aprilie 2015 16:27:30
Problema Arbori de intervale Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.38 kb
#include<stdio.h>
#include<algorithm>
using namespace std;

int a[100004],arb[100004*4];
int val,i,j,k,m,u,y,x,sol;
void build (int nod, int l ,int r)
{
    if (l==r) arb[nod]=a[r];
        else
        {
            int mijl=(l+r)/2;
            build(2*nod,l,mijl);
            build(2*nod+1,mijl+1,r);
            arb[nod]=max(arb[nod*2],arb[nod*2+1]);
        }
}

void update(int nod,int l, int r, int pos)
{
    if (l==r) arb[nod]=x;
        else
        {
            int mijl=(l+r)/2;
            if (pos<=mijl) update(2*nod,l,mijl,pos);
                    else update(2*nod+1,mijl+1,r,pos);
            arb[nod]=max(arb[nod*2],arb[nod*2+1]);
        }
}

int mx( int nod , int l,int r)
{
    if (x<=l && y>=r) sol=max(sol,arb[nod]);
        else
        {
            int mijl=(l+r)/2;
            if (x<=mijl) mx(nod*2,l,mijl);
            if (y>mijl)  mx(nod*2+1,mijl+1,r);
        }
    return sol;
}

int main()
{
    freopen("arbint.in","r",stdin);
    freopen("arbint.out","w",stdout);
    int n;
    scanf("%d%d",&n,&m);
    for (i=1; i<=n; ++i) scanf("%d",&a[i]);
    build(1,1,n);
    while (m--)
    {
        int op;
        scanf("%d%d%d",&op,&x,&y);
        if (!op) {sol=0; printf("%d\n",mx(1,1,n));}
            else
            {
                val=y;
                update(1,1,n,x);
            }
    }
 return 0;
}