Cod sursa(job #1972332)

Utilizator stefan_creastaStefan Creasta stefan_creasta Data 22 aprilie 2017 20:36:21
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.26 kb
#include <cstdio>
#include <algorithm>
using namespace std;
const int NMAX = 300000;
int v[NMAX];
void update(int nod, int st, int dr, int poz, int val)
{
    if(st == dr) {
        v[nod] = val;
        return ;
    }
    int mij = (st + dr) / 2;
    if(poz <= mij) {
        update(2 * nod, st, mij, poz, val);
    }
    else {
        update(2 * nod + 1, mij + 1, dr, poz, val);
    }
    v[nod] = max(v[2 * nod], v[2 * nod + 1]);
}
int query(int nod, int st, int dr, int a, int b)
{
    if(a <= st && dr <= b)
        return v[nod];
    int mij = (st + dr) / 2;
    int a1 = 0, a2 = 0;
    if(a <= mij) {
        a1 = query(2 * nod, st, mij, a, b);
    }
    if(b > mij) {
        a2 = query(2 * nod + 1, mij + 1, dr, a, b);
    }
    return max(a1, a2);
}

int main()
{
    int n, m, i, val, tip, a, b;
    freopen("arbint.in","r",stdin);
    freopen("arbint.out","w",stdout);
    scanf("%d%d", &n, &m);
    for(i = 1;i <= n; ++i) {
        scanf("%d", &val);
        update(1, 1, n, i, val);
    }
    for(i = 1;i <= m; ++i) {
        scanf("%d%d%d", &tip, &a, &b);
        if(tip == 0) {
            printf("%d\n", query(1, 1, n, a, b));
        }
        else {
            update(1, 1, n, a, b);
        }
    }
    return 0;
}