Cod sursa(job #1951723)

Utilizator MaligMamaliga cu smantana Malig Data 3 aprilie 2017 19:24:26
Problema Arbori de intervale Scor 40
Compilator cpp Status done
Runda Arhiva educationala Marime 1.42 kb
#include <iostream>
#include <fstream>

using namespace std;
ifstream in("arbint.in");
ofstream out("arbint.out");

const int arbMax = 131071 + 5;
const int NMax = 1e5 + 5;

int N,M;
int arb[arbMax];

void update(int,int,int,int,int);
int query(int,int,int,int,int);

int main() {
    /*
    int pw = 1;
    for (;pw < NMax;pw <<= 1) ;
    out<<pw*2 - 1<<'\n';
    //*/

    in>>N>>M;
    for (int i=1;i<=N;++i) {
        int val;
        in>>val;
        update(1,1,N,i,val);
    }

    while (M--) {
        int tip,a,b;
        in>>tip>>a>>b;
        if (tip == 0) {
            out << query(1,1,N,a,b) << '\n';
        }
        else {
            update(1,1,N,a,b);
        }
    }

    in.close();out.close();
    return 0;
}

void update(int nod,int st,int dr,int poz,int val) {
    if (st == dr) {
        arb[nod] = val;
        return;
    }

    int mij = (st+dr)>>1;
    if (poz <= mij) {
        update(nod<<1,st,mij,poz,val);
    }
    else {
        update((nod<<1)+1,mij+1,dr,poz,val);
    }
    arb[nod] = max(arb[nod<<1],arb[(nod<<1)+1]);
}

int query(int nod,int st,int dr,int a,int b) {
    if (a <= st && dr <= b) {
        return arb[nod];
    }

    int mij = (st+dr)>>1,
        mx = 0;
    if (a <= mij) {
        mx = query(nod<<1,st,mij,a,b);
    }
    if (mij+1 <= b) {
        mx = max(mx,query((nod<<1)+1,mij+1,dr,a,b));
    }
    return mx;
}