Cod sursa(job #2172917)

Utilizator RaduMirceaAndreiRadu Mircea Andrei RaduMirceaAndrei Data 15 martie 2018 19:01:13
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.17 kb
# include <fstream>
# define DIM 400005
using namespace std;
ifstream fin("arbint.in");
ofstream fout("arbint.out");
int arb[DIM],n,m,op,a,b,i;
void build(int nod,int st,int dr){
    if(st==dr){
        fin>>arb[nod];
        return;
    }
    int mij=(st+dr)/2;
    build(2*nod,st,mij);
    build(2*nod+1,mij+1,dr);
    arb[nod]=max(arb[2*nod],arb[2*nod+1]);
}
void update(int nod,int st,int dr,int poz,int val){
    if(st==dr){
        arb[nod]=val;
        return;
    }
    int mij=(st+dr)/2;
    if(poz<=mij)
        update(2*nod,st,mij,poz,val);
    else
        update(2*nod+1,mij+1,dr,poz,val);
    arb[nod]=max(arb[2*nod],arb[2*nod+1]);
}
int query(int nod,int st,int dr,int p,int u){
    if(p<=st&&u>=dr)
        return arb[nod];
    int mij=(st+dr)/2,val=0;
    if(p<=mij)
        val=max(val,query(2*nod,st,mij,p,u));
    if(u>mij)
        val=max(val,query(2*nod+1,mij+1,dr,p,u));
    return val;
}
int main () {
    fin>>n>>m;
    build(1,1,n);
    for(i=1;i<=m;i++){
        fin>>op>>a>>b;
        if(op==0){
            fout<<query(1,1,n,a,b)<<"\n";
            continue;
        }
        update(1,1,n,a,b);
    }
    return 0;
}