Cod sursa(job #2547676)

Utilizator AlexandruBrezuleanuAlexandruBrezuleanu AlexandruBrezuleanu Data 15 februarie 2020 16:11:13
Problema Arbori de intervale Scor 50
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.21 kb
#include <fstream>
#define MAX 400010
using namespace std;
ifstream fin("arbint.in");
ofstream fout("arbint.out");
int arb[MAX];
void update(int node,int st,int dr,int pos,int val);
int query(int node,int st,int dr,int x,int y);
int n,m;
int main()
{
    int i,ce,a,b,x;
    fin>>n>>m;
    for(i=1; i<=n; i++)
    {
        fin>>x;
        update(1,1,n,i,x);
    }
    for(i=1; i<=m; i++)
    {
        fin>>ce>>a>>b;
        if(ce==0)
            fout<<query(1,1,n,a,b)<<endl;
        else
            update(1,1,n,a,b);
    }
    return 0;
}
void update(int node,int st,int dr,int pos,int val)
{
    int mij;
    if(st==dr)
    {
        arb[node]=val;
        return;
    }
    mij=(st+dr)/2;
    if(pos<=mij)
        update(2*node,st,mij,pos,val);
    else
        update(2*node+1,mij+1,dr,pos,val);
    arb[node]=max(arb[2*node],arb[2*node+1]);

}
int query(int node,int st,int dr,int x,int y)
{
    int mij,ansl=0,ansr=0;
    if(x<=st&&dr<=y)
        return arb[node];
    else
    {
        mij=(st+dr)/2;
        if(x<=mij)
            ansl=query(2*node,st,mij,x,y);
        if(mij<y)
            ansr=query(2*node+1,mij+1,dr,x,y);
        return max(ansl,ansr);
    }
}