Cod sursa(job #2485973)

Utilizator ioanaa_ghGhiorghi Ioana-Cristina ioanaa_gh Data 2 noiembrie 2019 10:57:18
Problema Arbori indexati binar Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.29 kb
#include <bits/stdc++.h>

using namespace std;

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

int n, x, aib[100005], m;

void Update(int p, int x)
{
    while(p <= n)
    {
        aib[p] += x;
        p += (p & (-p));
    }
}

int Suma(int p)
{
    int s = 0;
    while(p > 0)
    {
        s += aib[p];
        p -= (p & (-p));
    }
    return s;
}

int CB(int p, int x)
{
    int st, dr, mij, poz, suma = 0;
    st = 1;
    dr = p;
    poz = -1;
    while(st <= dr)
    {
        mij = (st + dr) / 2;
        suma = Suma(mij);
        if(suma == x)
        {
            poz = mij;
            dr = mij - 1;
        }
        else if(suma > x)
            dr = mij - 1;
        else st = mij + 1;
    }
    return poz;
}

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