Cod sursa(job #3290729)

Utilizator stefan_dore_Stefan Dore stefan_dore_ Data 31 martie 2025 18:48:46
Problema Arbori de intervale Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.21 kb
#include <iostream>
#include <fstream>
using namespace std;

ifstream f ("arbint.in");
ofstream g ("arbint.out");

const int NMAX = 100000;
int Ai[NMAX+1];

void Update(int rad, int st, int dr, int poz, int val) {
    if (st == dr)
        Ai[rad] = val;
    else {
        int m = (st + dr) / 2;
        if (poz <= m)
            Update(2*rad, st, m, poz, val);
        else
            Update(2*rad+1, m+1, dr, poz, val);
        Ai[rad] = max(Ai[2*rad], Ai[2*rad+1]);
    }
}

int Query(int rad, int st, int dr, int a, int b) {
    if (a <= st && dr <= b)
        return Ai[rad];
    else {
        int m = (st + dr) / 2,
            r1, r2;
        if (a <= m)
            r1 = Query(2*rad, st, m, a, b);
        if (b > m)
            r2 = Query(2*rad+1, m+1, dr, a, b);
        return max(r1, r2);
    }
}

int main(){
    int N, M, op, a, b;
    f >> N >> M;
    //
    for (int i=1; i<=N; i++) {
        f >> a;
        Update(1, 1, N, i, a);
    }
    //
    while(M--) {
        f >> op >> a >> b;
        if (op == 0)
            g << Query(1, 1, N, a, b) << '\n';
        else
            Update(1, 1, N, a, b);
    }
    //
    f.close();
    g.close();
    return 0;
}