Cod sursa(job #1571266)

Utilizator depevladVlad Dumitru-Popescu depevlad Data 17 ianuarie 2016 18:02:54
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.04 kb
#include <fstream>
#include <algorithm>

using namespace std;

const int MAX_N = 100000;

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

int n, m;
int T[2 * MAX_N + 1];

void buildTree() {
    for(int i = n; i; i--) {
        T[i] = max(T[i << 1], T[i << 1 | 1]);
    }
}

void updateTree(int p, int val) {
    for(T[p += n] = val; p > 1; p >>= 1) {
        T[p >> 1] = max(T[p], T[p ^ 1]);
    }
}

int queryTree(int l, int r) {
    int ans = 0;
    for(l += n, r += n; l < r; l >>= 1, r >>= 1) {
        if(l & 1) {
            ans = max(ans, T[l++]);
        }
        if(r & 1) {
            ans = max(ans, T[--r]);
        }
    }
    return ans;
}

int main() {
    int i, t, a, b;

    in >> n >> m;
    for(i = 1; i <= n; i++) {
        in >> T[n + i];
    }
    buildTree();
    for(i = 1; i <= m; i++) {
        in >> t >> a >> b;
        if(t == 0) {
            out << queryTree(a, b + 1) << '\n';
        }
        else {
            updateTree(a, b);
        }
    }

    return 0;
}