Cod sursa(job #999392)

Utilizator a96tudorAvram Tudor a96tudor Data 20 septembrie 2013 09:16:49
Problema Arbori de intervale Scor 50
Compilator cpp Status done
Runda Arhiva educationala Marime 1.41 kb
#include<cstdio>
#include<algorithm>
#include<cmath>

#define INF 1000000000
using namespace std;

int T[400010],a[100010];
int x,y,n,m,i,sol,k;

// interogare

inline int ArbQwery(int nod,int st,int dr,int x,int y)
{
    if (st>=x && y>=dr) return T[nod];
    int mij=(st+dr)/2;
    int sol=-INF;
    if (x<=mij) sol=max(sol,ArbQwery(nod*2,st,mij,x,y));
    if (mij<y) sol=max(sol,ArbQwery(nod*2+1,mij+1,dr,x,y));
    return sol;
}

//actualizare

inline void ArbUpdate(int nod,int st,int dr,int poz,int nr)
{
    if (st==dr)
        {
            T[nod]=nr;
            return;
        }
    int mij=(st+dr)/2;
    if (poz<=mij) ArbUpdate(nod*2,st,mij,poz,nr);
            else ArbUpdate(nod*2+1,mij+1,dr,poz,nr);
    T[nod]=max(T[nod*2],T[nod*2+1]);
}

int main()
{
    freopen("arbint.in","r",stdin);
    freopen("arbint.out","w",stdout);
    scanf("%d%d",&n,&m);

    for (i=1;i<=n;i++)
    {
        scanf("%d",&a[i]);
        ArbUpdate(1,1,n,i,a[i]);
    }

    for (i=1;i<=m;i++)
    {
        sol=-INF;
        scanf("%d%d%d",&k,&x,&y);
        if (k==1)
                {
                    a[x]=y;
                    ArbUpdate(1,1,n,x,a[x]);
                }
            else
                {
                    sol=ArbQwery(1,1,n,x,y);
                    printf("%d\n",sol);
                }
    }

    fclose(stdin);
    fclose(stdout);
    return 0;
}