Cod sursa(job #2775192)

Utilizator cyg_dragos10Ivan Dragos cyg_dragos10 Data 14 septembrie 2021 20:51:30
Problema Arbori indexati binar Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.24 kb
#include <fstream>

using namespace std;

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

const int NMAX = 100005;
long long v[NMAX],n,q;

void update(int a,int b)
{
    while(a <= n)
    {
        v[a] += b;
        a += a & -a;
    }
}

int query(int a)
{
    int s = 0;
    while(a > 0)
    {
        s += v[a];
        a -= a & -a;
    }
    return s;
}

int f2(int a, int b)
{
    int st = 1,dr = b;
    while(st <= dr)
    {
        int mij = (st + dr) / 2;
        int s = query(mij);
        if(s == a)
        {
            return mij;
        }
        if(s < a)
        {
            st = mij + 1;
        }
        else
        {
            dr = mij - 1;
        }
    }
    return -1;
}

int main()
{
    long long a,b,c;
    fin>>n>>q;
    for(int i = 1;i <= n;i++)
    {
        fin>>a;
        update(i,a);
    }
    for(int i = 1;i <= q;i++)
    {
        fin>>c>>a;
        if(c == 2)
        {
            fout<<f2(a,n)<<"\n";
        }
        else
        {
            fin>>b;
            if(c == 1)
            {
                fout<<query(b) - query(a - 1)<<"\n";
            }
            else
                update(a, b);
        }
    }
    return 0;
}