Cod sursa(job #2779755)

Utilizator XsoundCristian-Ioan Roman Xsound Data 4 octombrie 2021 20:52:47
Problema Arbori de intervale Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 3.31 kb
#include<bits/stdc++.h>
using namespace std;

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

int n, m;
vector<int> v;

int intervalTree[300005];

void BuildIntervalTree(int st, int dr, int nodePosition);

int GetMaxValueInRange(int leftRangeLimit, int rightRangeLimit, int st, int dr, int nodePosition);

int UpdateIntervalTree(int position, int value, int nodePosition, int st, int dr);

int main()
{
    fin >> n >> m;

    for(int i = 0; i < n; i++)
    {
        int x;
        fin >> x;
        v.push_back(x);
    }

    BuildIntervalTree(0, n-1, 0);

    for(int i = 0; i < m; i++)
    {
        int questionType;
        fin >> questionType;

        if(questionType==0)
        {
            int leftRangeLimit, rightRangeLimit;
            fin >> leftRangeLimit >> rightRangeLimit;

            fout << GetMaxValueInRange(leftRangeLimit-1, rightRangeLimit-1, 0, n-1, 0);
        }
        else
        {
            int position, value;

            fin >> position >> value;

            v[position] = value;

            UpdateIntervalTree(position-1, value, 0, 0, n-1);
        }
    }

}

int UpdateIntervalTree(int position, int value, int nodePosition, int st, int dr)
{
    if(st==dr)
    {
        intervalTree[nodePosition] = value;
        return value;
    }
    int mij = (st+dr)/2;

    int leftNodePosition = nodePosition*2+1;
    int rightNodePosition = nodePosition*2+2;

    if(position<=mij)
    {
        intervalTree[leftNodePosition] = UpdateIntervalTree(position, value, leftNodePosition, st, mij);
    }
    else
    {
        intervalTree[rightNodePosition] = UpdateIntervalTree(position, value, rightNodePosition, mij+1, dr);
    }

    int leftNodeValue = intervalTree[leftNodePosition];
    int rightNodeValue = intervalTree[rightNodePosition];

    intervalTree[nodePosition] = max(leftNodeValue, rightNodeValue);
    return intervalTree[nodePosition];
}

int GetMaxValueInRange(int leftRangeLimit, int rightRangeLimit, int st, int dr, int nodePosition)
{
    if(st==dr)
    {
        return intervalTree[nodePosition];
    }

    if(leftRangeLimit<=st && rightRangeLimit>=dr)
    {
        return intervalTree[nodePosition];
    }

    int mij = (st+dr)/2;

    int leftNodeValue, rightNodeValue;

    if(leftRangeLimit>mij)
    {
        leftNodeValue = 0;
    }
    else
    {
        int leftNodePosition = nodePosition*2+1;
        leftNodeValue = GetMaxValueInRange(leftRangeLimit, mij, st, mij, leftNodePosition);
    }

    if(rightRangeLimit <= mij)
    {
        rightNodeValue = 0;
    }
    else
    {
        int rightNodePosition = nodePosition*2+2;
        rightNodeValue = GetMaxValueInRange(mij+1, rightRangeLimit, mij+1, dr, rightNodePosition);
    }

    return max(leftNodeValue, rightNodeValue);

}

void BuildIntervalTree(int st, int dr, int nodePosition)
{
    if(st==dr)
    {
        intervalTree[nodePosition] = v[st];
        return;
    }

    int mij = (st+dr)/2;

    int leftNodePosition = nodePosition*2+1;
    int rightNodePosition = nodePosition*2+2;

    BuildIntervalTree(st, mij, leftNodePosition);
    BuildIntervalTree(mij+1, dr, rightNodePosition);

    intervalTree[nodePosition] = max(intervalTree[leftNodePosition], intervalTree[rightNodePosition]);
}