Cod sursa(job #2187184)

Utilizator AlexutAlex Calinescu Alexut Data 26 martie 2018 11:57:26
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.43 kb
#include<fstream>
#include <algorithm>
using namespace std;
ifstream cin ("arbint.in");
ofstream cout ("arbint.out");
int v[100005];
long long aint[400010];
long long sol;
void build(int nod,int st,int dr)
{
    if(st==dr)
        aint[nod]=v[st];
    else
    {
        int med=(st+dr)/2;
        build(2*nod,st,med);
        build(2*nod+1,med+1,dr);
        aint[nod]=max(aint[2*nod],aint[2*nod+1]);
    }
    
}
void update(int nod,int st,int dr, int pozv,int new_val)
{
    if(st==dr)
        aint[nod]=new_val;
    else
    {
        int med=(st+dr)/2;
        if(pozv<=med)
        update(2*nod,st,med,pozv,new_val);
        if(pozv>=med+1)
        update(2*nod+1,med+1,dr,pozv,new_val);
        aint[nod]=max(aint[2*nod],aint[2*nod+1]);
    }
}
void query(int nod,int st,int dr,int a,int b)
{
    if(a<=st && dr<=b)
        sol=max(sol,aint[nod]);
    else
    {
        int med=(st+dr)/2;
        if(a<=med)
            query(2*nod,st,med,a,b);
        if(b>=med+1)
        query(2*nod+1,med+1,dr,a,b);
    }
}
int main() 
{
    int n,m,i,j;
    cin>>n>>m;
    for(i=1;i<=n;i++)
    {
        cin>>v[i];
    }
    build(1,1,n);
    int x,y,z;
    for(i=1;i<=m;i++)
    {
        cin>>x>>y>>z;
        if(x==1)
        {
            update(1,1,n,y,z);
        }
        else
        {
            sol=0;
            query(1,1,n,y,z);
            cout<<sol<<"\n";
        }
    }
}