Cod sursa(job #1254265)

Utilizator smallOneAdina Mateescu smallOne Data 2 noiembrie 2014 14:09:49
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 2 kb
#include <cstdio>
#include <iostream>
#include <fstream>
#include <vector>
#include <list>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <bitset>
#include <algorithm>
#include <sstream>
#include <iomanip>
#include <cmath>
#include <cstdlib>
#include <ctype.h>
#include <cstring>
#include <string>
#include <ctime>
#include <cassert>
#include <utility>
#define LIM 100001

using namespace std;

int pos, val, n, a, b, maxim, v[LIM];
int A[4 * LIM];

void initARB(int nod, int st, int dr) {
    if(st == dr) {
       A[nod] = v[st];
       return;
    }
    int mij = (st + dr) / 2;
    initARB(2 * nod, st, mij);
    initARB(2 * nod + 1, mij + 1, dr);

    A[nod] = max(A[2 * nod], A[2 * nod + 1]);
}

void updateARB(int nod, int st, int dr) {
    if(st == dr) {
       A[nod] = val;
       return;
    }
    int mij = (st + dr) / 2;
    if(pos <= mij) {
        updateARB(2 * nod, st, mij);
    }
    else {
        updateARB(2 * nod + 1, mij + 1, dr);
    }

    A[nod] = max(A[2 * nod], A[2 * nod + 1]);
}

void queryARB(int nod, int st, int dr) {
    if(a <= st && dr <= b) {
        if(maxim < A[nod]) {
            maxim = A[nod];
        }
        return;
    }
    // aici incerc sa includ intervalul [st, dr] in intervalul [a, b]
    int mij = (st + dr) / 2;
    if(a <= mij) {
        queryARB(2 * nod, st, mij);
    }
    if(mij < b) {
        queryARB(2 * nod + 1, mij + 1, dr);
    }
}

int main() {
	freopen("arbint.in", "r", stdin);
	freopen("arbint.out","w", stdout);
    int m, op;

    scanf("%d %d", &n, &m);
    for(int i = 1; i <= n; i++) {
        scanf("%d", &v[i]);
    }
    initARB(1, 1, n);

    for(int i = 0; i < m; i++) {
        scanf("%d %d %d", &op, &a, &b);
        if(op == 0) {
            maxim = -1;
            queryARB(1, 1, n);
            printf("%d\n", maxim);
        } else {
            pos = a;
            val = b;
            updateARB(1, 1, n);
        }
    }

	return 0;
}