Cod sursa(job #2575609)

Utilizator DobondiDavidDobondiDavid DobondiDavid Data 6 martie 2020 14:38:45
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.23 kb
#include <bits/stdc++.h>

using namespace std;
ifstream fin("arbint.in");
ofstream fout("arbint.out");
#define cin fin
#define cout fout
#define left(nod) (nod * 2)
#define right(nod) (nod * 2 + 1)
const int NMAX=1e5+50;
int v[4*NMAX];


void update(int nod,int st,int dr,int pos,int val)
{
    if(st==dr)
        v[nod]=val;
    else
    {
        int m=(st+dr)/2;
        if(pos<=m)
            update(left(nod),st,m,pos,val);
        else
            update(right(nod),m+1,dr,pos,val);

        v[nod]=max(v[left(nod)],v[right(nod)]);
    }
}


int query(int nod,int st,int dr,int a,int b)
{

    int m,x1=0,x2=0;
    if(a<=st && dr<=b)
        return v[nod];
    else
    {
        m=(st+dr)/2;
        if(a<=m)
            x1=query(left(nod),st,m,a,b);
        if(b>=m+1)
            x2=query(right(nod),m+1,dr,a,b);

        return max(x1,x2);
    }

}



int n,i,a,b,m,val,x;

int main()
{
    cin >> n >> m;
    for(i=1;i<=n;i++)
    {
        cin >> val;
        update(1,1,n,i,val);
    }

    for(i=1;i<=m;i++)
    {
        cin >> x >> a >> b;
        if(x==1)
            update(1,1,n,a,b);
        else
            cout << query(1,1,n,a,b) << '\n';
    }



    return 0;
}