Cod sursa(job #2573003)

Utilizator stefan_creastaStefan Creasta stefan_creasta Data 5 martie 2020 15:21:27
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.37 kb
#include <cstdio>
#include <algorithm>
using namespace std;
const int NMAX = 100005;
int aint[NMAX * 4];
void update(int nod, int st, int dr, int poz, int val) {
    if(st == dr) {
        aint[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);
    }
    aint[nod] = max(aint[2 * nod], aint[2 * nod + 1]);
}
int query(int nod, int st, int dr, int x, int y) {
    if(st > dr) {
        return 0;
    }
    if(x <= st && dr <= y) {
        return aint[nod];
    }
    int mij = (st + dr) / 2;
    int sol1 = 0, sol2 = 0;
    if(x <= mij) {
        sol1 = query(2 * nod, st, mij, x, y);
    }
    if(mij < y) {
        sol2 = query(2 * nod + 1, mij + 1, dr, x, y);
    }
    return max(sol1, sol2);
}

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