Cod sursa(job #2575369)

Utilizator alisavaAlin Sava alisava Data 6 martie 2020 13:07:32
Problema Arbori indexati binar Scor 30
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.61 kb
#include <bits/stdc++.h>
#define lung(x) ( (x^(x- 1)) & x )


using namespace std;

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

int  aib[17000];
int n, m;

void Update(int poz,int val)
{
    for(int i = poz; i <= 10000; i += lung(i))
        aib[i] += val;
}

int Query(int poz)
{
    int answer = 0;
    for(int i = poz; i >= 1; i -= lung(i))
        answer += aib[i];
    return answer;

}
int BinSearch(int val)
{
    int suma = 0;
    int raspuns = 0;
    int FinalAnswer = 1e9;
    for(int i = 13; i >= 0; i --)
    {
        //cout << suma << " " << raspuns << " " << raspuns + (1 << i) << " " << aib[raspuns + (1 << i)] <<" " << val << "\n";
        if(suma + aib[raspuns + (1 << i)] < val)
        {
            suma +=  aib[raspuns + (1 << i)];
            raspuns += (1 << i);
        }
        else if(suma + aib[raspuns + (1 << i)] == val)
        {
            FinalAnswer = min(FinalAnswer, raspuns + (1 << i));
        }
    }
    if(FinalAnswer == 1e9)
        return -1;
    return FinalAnswer;
}



int main()
{
    int a, b, op, x;
    fin >> n >> m;
    for(int i = 1; i <= n; i++)
    {
        fin >> x;
        Update(i, x);
    }
    for(int i = 1 ; i <= m; i++)
    {
        fin >> op;
        if(op == 0)
        {
            fin >> a >> b;
            Update(a, b);
        }
        else if(op == 1)
        {
            fin >> a >> b;
            fout << Query(b) - Query(a - 1) << "\n";
        }
        else
        {
            fin >> a;
            fout << BinSearch(a) <<"\n";
        }



    }


    return 0;
}