Cod sursa(job #2696627)

Utilizator balintfranceskaBalint Franceska balintfranceska Data 16 ianuarie 2021 11:12:21
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.33 kb
#include <bits/stdc++.h>
using namespace std;
ifstream f("arbint.in"); ofstream g("arbint.out");
int n, q, v[100002], aint[400002];
void build(int nod, int st, int dr)
{   if(st==dr)
    {   aint[nod]=v[st];
        return;
    }
    int mid=(st+dr)/2;
    build(nod<<1, st, mid);
    build(nod<<1|1, mid+1, dr);
    aint[nod]=max(aint[nod<<1], aint[nod<<1|1]);
}
void update(int nod, int st, int dr, int poz, int val)
{   if(st==dr)
    {   aint[nod]=val;
        return;
    }
    int mid=(st+dr)/2;
    if(poz<=mid)
        update(nod<<1, st, mid, poz, val);
    else
        update(nod<<1|1, mid+1, dr, poz, val);
    aint[nod]=max(aint[nod<<1], aint[nod<<1|1]);
}
int query(int nod, int st, int dr, int L, int R)
{   if(dr<L || st>R) return -1;
    if(L<=st && dr<=R) return aint[nod];
    int mid=(st+dr)/2;
    return max(query(nod<<1, st, mid, L, R), query(nod<<1|1, mid+1, dr, L, R));
}
int main()
{   f>>n>>q;
    for(int i=1; i<=n; ++i) f>>v[i];
    build(1, 1, n);
    for(int i=1; i<=q; ++i)
    {   int tip;
        f>>tip;
        if(tip==0)
        {   int L, R;
            f>>L>>R;
            g<<query(1, 1, n, L, R)<<'\n';
        }
        else
        {   int poz, val;
            f>>poz>>val;
            update(1, 1, n, poz, val);
        }
    }
    f.close(); g.close(); return 0;
}