Cod sursa(job #2254415)

Utilizator andreisontea01Andrei Sontea andreisontea01 Data 5 octombrie 2018 12:17:38
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.19 kb
#include <fstream>
#include <iostream>

using namespace std;

const int MAXN = 100005;

int v[MAXN], arb[4 * MAXN];

int maxinter(int nod, int st, int dr, int a, int b){
    if(a <= st && dr <= b)
        return arb[nod];
    int mij = (st + dr) / 2;
    int LeftMax = 0, RightMax = 0;
    if(a <= mij)
        LeftMax = maxinter(2 * nod, st, mij, a, b);
    if(b > mij)
        RightMax = maxinter(2 * nod + 1, mij + 1, dr, a, b);
    return max(LeftMax, RightMax);
}

void update(int nod, int st, int dr, int a, int b){
    if(st == dr && st == a){
        arb[nod] = b;
        return;
    }
    int mij = (st + dr) / 2;
    if(a <= mij)
        update(2 * nod, st, mij, a, b);
    else
        update(2 * nod + 1, mij + 1, dr, a, b);
    arb[nod] = max(arb[2 * nod], arb[2 * nod + 1]);
}

int main()
{
    ifstream fin("arbint.in");
    ofstream fout("arbint.out");
    int n, m;
    fin >> n >> m;
    for(int i = 1; i <= n; ++i){
        fin >> v[i];
        update(1, 1, n, i, v[i]);
    }
    int q, a, b;
    for(int quer = 1; quer <= m; ++quer){
        fin >> q >> a >> b;
        if(!q)
            fout << maxinter(1, 1, n, a, b) << "\n";
        else
            update(1, 1, n, a, b);
    }
    return 0;
}