Cod sursa(job #2002314)

Utilizator razvandraghiciDraghici Razvan razvandraghici Data 19 iulie 2017 13:38:48
Problema Arbori de intervale Scor 40
Compilator cpp Status done
Runda Arhiva educationala Marime 1.47 kb
#include <fstream>

using namespace std;

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

int n, m, i, sol, A[200003], a, b, c, d, e;

void build(int nod, int st, int dr){
    if(st == dr){
        fin>>A[nod];
    }
    else{
            int mid = (st + dr) / 2;
            build(2 * nod, st, mid);
            build(2 * nod + 1, mid + 1, dr);
            A[nod]=max(A[2 * nod], A[2 * nod + 1]);
        }
}

int query(int nod, int st, int dr, int a, int b){
    if(a <= st && b >= dr){
        sol=max(sol, A[nod]);
    }
    else{
        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);
    }
    return sol;
}

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

int main()
{
    fin>>n>>m;

    build(1, 1, n);

    for(i = 1;i <= m;i++){
        sol = -1;
        fin>>c>>a>>b;
        if(c == 0){
            fout<<query(1, 1, n, a, b)<<'\n';
        }
        else{
            update(1, 1, n, a, b);
        }
    }


    return 0;
}