Cod sursa(job #1405146)

Utilizator SagunistuStrimbu Alexandru Sagunistu Data 28 martie 2015 21:43:23
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.36 kb
#include <cstdio>
#define nmax 100005

using namespace std;

int a[4*nmax],n,m,poz,val,start,finish,maxim;

int mxm(int a,int b)
{
    if(a>b)
        return a;
    return b;
}

void update(int nod,int st,int dr)
{
    if(st==dr)
        a[nod]=val;
    else
    {
        int m=(st+dr)/2;
        if(poz<=m)
            update(2*nod,st,m);
        else
            update(2*nod+1,m+1,dr);
        a[nod]=mxm(a[2*nod],a[2*nod+1]);
    }
}

void get(int nod,int st,int dr)
{
    if(start<=st&&dr<=finish)
    {
        if(maxim<a[nod])
            maxim=a[nod];
    }
    else
    {
        int m=(st+dr)/2;
        if(start<=m)
            get(2*nod,st,m);
        if(m<finish)
            get(2*nod+1,m+1,dr);
    }
}

int main()
{
    freopen("arbint.in","r",stdin);
    freopen("arbint.out","w",stdout);
    int t,x,y;
    scanf("%d%d",&n,&m);
    for(int i=1;i<=n;i++)
    {
        scanf("%d",&x);
        poz=i;
        val=x;
        update(1,1,n);
    }
    for(int i=1;i<=m;i++)
    {
         scanf("%d%d%d",&t,&x,&y);
        if(t==0)
        {
            start=x;
            finish=y;
            maxim=-1;
            get(1,1,n);
            printf("%d\n",maxim);
        }
        else
        {
            val=y;
            poz=x;
            update(1,1,n);
        }
    }
    return 0;
}