Cod sursa(job #2687235)

Utilizator Xutzu358Ignat Alex Xutzu358 Data 19 decembrie 2020 16:59:41
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.11 kb
#include <bits/stdc++.h>
using namespace std;

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

int aint[400005];
int a,b;
int n,m;
int x;
int op;

int get_max(int pos, int st, int dr, int aa, int bb) {
    if (bb < st || aa > dr) {
        return 0;
    }
    if (dr <= bb && aa <= st) {
        return aint[pos];
    }
    int mid = (st+dr)/2;
    return max(get_max(2*pos,st,mid,aa,bb),get_max(2*pos+1,mid+1,dr,aa,bb));
}

void update(int pos, int st, int dr, int elem, int val) {
    if (elem < st || dr < elem) {
        return;
    }
    if (st == dr) {
        aint[pos] = val;
        return ;
    }
    int mid = (st+dr)/2;
    update(2*pos,st,mid,elem,val);
    update(2*pos+1,mid+1,dr,elem,val);
    aint[pos] = max(aint[2*pos],aint[2*pos+1]);
}

int main()
{

    f >> n >> m;
    for (int i=1;i<=n;i++) {
        f >> x;
        update(1,1,n,i,x);
    }
    for (int i=1;i<=m;i++) {
        f >> op >> a >> b;
        if (op == 0) {
            g << get_max(1,1,n,a,b) << '\n';
        }
        else {
            update(1,1,n,a,b);
        }
    }
    return 0;
}