Cod sursa(job #2937795)

Utilizator gabriel.9619Gabriel Stefan Tita gabriel.9619 Data 11 noiembrie 2022 00:01:57
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.53 kb
#include <fstream>
using namespace std;
ifstream fin("arbint.in");
ofstream fout("arbint.out");
int A[400001], v[100001], sol;

void build(int nod, int st, int dr)
{
    if(st==dr)
    {
            A[nod]=v[st];
    }
    else
    {
        int mid=(st+dr)/2;
        build(2*nod, st, mid);
        build(2*nod+1, mid+1, dr);
        A[nod]=max(A[2*nod], A[2*nod+1]);
    }
}

void update(int nod, int st, int dr, int poz, int valoare)
{
    if(st==dr)
    {
        A[nod]=valoare;
    }
    else
    {
        int mid=(st+dr)/2;
        if(poz<=mid)
        {
            update(2*nod, st, mid, poz, valoare);
        }
        else
        {
            update(2*nod+1, mid+1, dr, poz, valoare);
        }
        A[nod]=max(A[2*nod], A[2*nod+1]);
    }
}

void query(int nod, int st, int dr, int a, int b)
{
    if(a<=st&&dr<=b)
    {
        sol=max(sol, A[nod]);
    }
    else
    {
        int mid=(st+dr)/2;
        if(a<=mid)
        {
            query(2*nod, st, mid, a, b);
        }
        if(mid+1<=b)
        {
            query(2*nod+1, mid+1, dr, a, b);
        }
    }
}

int main()
{
    int n, i, m, a, b, c;
    fin>>n>>m;
    for(i=1;i<=n;i++)
    {
        fin>>v[i];
    }
    build(1, 1, n);
    for(i=1;i<=m;i++)
    {
        fin>>c>>a>>b;
        if(c==0)
        {
            sol=0;
            query(1, 1, n, a, b);
            fout<<sol<<"\n";
        }
        else
        {
            update(1, 1, n, a, b);
        }
    }
    return 0;
}