Cod sursa(job #3158802)

Utilizator Bianca2507Negret Bianca Bianca2507 Data 19 octombrie 2023 20:37:34
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.29 kb
#include <fstream>
#include <climits>
using namespace std;
ifstream cin("arbint.in");
ofstream cout("arbint.out");
int n,m,ce,A[4*100001],x,y,maxi;
void build(int nod,int st,int dr)
{
    if(st==dr)
    cin>>A[nod];
    else
    {
        int mid=(st+dr)/2;
        build(2*nod,st,mid);
        build(2*nod+1,mid+1,dr);
        A[nod]=max(A[nod*2],A[2*nod+1]);
    }
}
void update(int nod,int st,int dr,int a,int b)
{
    if(st==dr)
        A[nod]=b;
    else
    {
        int mid=(st+dr)/2;
        if(a<=mid)
            update(2*nod,st,mid,a,b);
        if(a>mid)
            update(2*nod+1,mid+1,dr,a,b);
        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)
        maxi=max(maxi,A[nod]);
    else
    {
        int mid=(st+dr)/2;
        if(a<=mid)
            query(2*nod,st,mid,a,b);
        if(b>mid)
            query(2*nod+1,mid+1,dr,a,b);
    }
}
int main()
{
    cin>>n>>m;
    build(1,1,n);
    for(int i=1;i<=m;i++)
    {
        cin>>ce>>x>>y;
        if(ce==0)
        {
            maxi=INT_MIN;
            query(1,1,n,x,y);
            cout<<maxi<<'\n';
        }
        else
            if(ce==1)
        {
            update(1,1,n,x,y);
        }
    }
    return 0;
}