Cod sursa(job #2110697)

Utilizator sebi110Ciobanu Sebastian sebi110 Data 21 ianuarie 2018 11:02:21
Problema Arbori de intervale Scor 30
Compilator cpp Status done
Runda Arhiva educationala Marime 1.16 kb
#include <fstream>

using namespace std;
ifstream fin("arbint.in");
ofstream fout("arbint.out");
int a[400004],pos,val,x,y;
int calc(int nod,int st,int dr)
{
    int rez=0,mij=(st+dr)/2;
    if(x<=st && dr<=y)
        rez=a[nod];
    if(x<=mij && a[nod*2]!=0)
        rez=max(rez,calc(nod*2,st,mij));
    if(mij<y && a[nod*2+1]!=0)
        rez=max(rez,calc(nod*2+1,mij+1,dr));
    return rez;
}
int act(int nod,int st,int dr)
{
    if(st==dr && st==pos)
    {
        a[nod]=val;
        return a[nod];
    }
    int mij=(st+dr)/2;
    if(pos<=mij)
    {
        a[nod]=max(act(nod*2,st,mij),a[nod*2+1]);
        return a[nod];
    }
    if(mij<pos)
    {
        a[nod]=max(a[nod*2],act(nod*2+1,mij+1,dr));
        return a[nod];
    }
}
int main()
{
    int n,m,i,op;
    fin>>n>>m;
    for(i=1;i<=n;i++)
    {
        fin>>x;
        pos=i;
        val=x;
        act(1,1,n);
    }
    for(i=1;i<=m;i++)
    {
        fin>>op>>x>>y;
        if(op==0)
        {
            fout<<calc(1,1,n)<<'\n';
        }
        else
        {
            pos=x;
            val=y;
            act(1,1,n);
        }
    }
    return 0;
}