Cod sursa(job #1690937)

Utilizator Vertex10Alexandru Pokharel Vertex10 Data 16 aprilie 2016 12:35:53
Problema Arbori indexati binar Scor 50
Compilator cpp Status done
Runda Arhiva educationala Marime 1.29 kb
#include <fstream>
#define zeros(x) ( (x ^ (x - 1)) & x )

using namespace std;
ifstream f("aib.in");
ofstream g("aib.out");
int n, m, AIB[100002];

void Add(int x, int quantity)
{
    int i;
    for (i = x; i <= n; i += zeros(i))
        AIB[i] += quantity;
}

int Compute(int x)
{
    int i, ret = 0;
    for (i = x; i > 0; i -= zeros(i))
        ret += AIB[i];
    return ret;
}

int main()
{
    f >> n >> m;
    int x;
    for(int i=1; i<=n; ++i)
    {
        f >> x;
        Add(i, x);
    }
    //for(int i=1; i<=n; ++i)
        //g << AIB[i] << " ";

    for (int i=1; i<=m; ++i)
    {
        int val, poz=0, a, b;
        f >> x;
        if (!x)
        {
            f >> poz >> val;
            Add(poz, val);
        }
        else if (x==1)
        {
            f >> a >> b;
            g << (Compute(b) - Compute(a-1)) << '\n';
        }
        else //cautarea binara
        {
            int x;
            f >> x;
            int pas = 131072; //2^17
            while(pas)
            {
                if (poz+pas<=n && AIB[poz+pas]<=x)
                {
                    x -= AIB[poz+pas];
                    poz += pas;
                }
                pas/=2;
            }
            if (x == 0) g << poz << '\n';
            else g << "-1" << '\n';
        }
    }

    return 0;
}