Cod sursa(job #1424639)

Utilizator klbraduRadu Capalb klbradu Data 25 aprilie 2015 10:22:46
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.07 kb
#include <fstream>
using namespace std;
int n, m, i, v[400004], x, a, b, maxim, op;

ifstream fin("arbint.in");
ofstream fout("arbint.out");

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

void query(int nod,int st, int dr, int a, int b){
    if(st >= a && dr <= b){
        maxim = max(maxim, v[nod]);
        return;
    }
    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(){
    fin>>n>>m;
    for(i=1;i<=n;i++){
        fin>>x;
        update(1,1,n,i,x);
    }
    for(i=1;i<=m;i++){
        fin>>op>>a>>b;
        if(op == 0){
            maxim=-2000000000;
            query(1,1,n,a,b);
            fout<<maxim<<"\n";
        }else{
            update(1,1,n,a,b);
        }
    }
}