Cod sursa(job #2932028)

Utilizator SeracovanuEdwardSeracovanu Edward SeracovanuEdward Data 1 noiembrie 2022 17:40:33
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.22 kb
#include <bits/stdc++.h>

using namespace std;

int const nmax = 100000;
int const inf = 1e9;

int n , m;
int p , v;
int l , r;
int T[4 * nmax + 5] , A[nmax + 5];

void build(int i,int j,int k){
if(i != j){
    build(i , (i + j) / 2,2 * k);
    build((i + j) / 2 + 1 , j,2 * k + 1);
    T[k] = max(T[2 * k],T[2 * k + 1]);
}else
    T[k] = A[i];
}

void update(int i,int j,int k){
if(i != j){
    int mid = (i + j) / 2;
    if(p <= mid)
        update(i , mid , 2 * k);
    else update(mid + 1,j , 2 * k + 1);
    T[k] = max(T[2 * k], T[2 * k + 1]);
}else
    T[k] = v;
}

int query(int i,int j,int k){
if(i > r || j < l)return -inf;
if(l <= i && j <= r)return T[k];
return max(query(i , (i + j) / 2, 2 * k) , query((i + j) / 2 + 1 , j,  2 * k + 1));
}

int main()
{
    freopen("arbint.in" , "r" , stdin);
    freopen("arbint.out" , "w" ,stdout);
    cin.tie(0)->sync_with_stdio(0);
    cin.exceptions(cin.failbit);
    cin >> n >> m;
    for(int i = 1;i <= n; ++i)cin >> A[i];
    build(1,n,1);
    for(int i = 1;i <= m; ++i){
        int op;
        cin >> op;
        if(op == 0){
            cin >> l >> r;
            cout << query(1 , n , 1) << "\n";
        }else{
            cin >> p >> v;
            update(1,n,1);
        }
    }
}