Cod sursa(job #3240088)

Utilizator nistor_dora_valentinaNistor Dora Valentina nistor_dora_valentina Data 12 august 2024 14:06:59
Problema Arbori indexati binar Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.19 kb
#include <fstream>

using namespace std;
ifstream fin("aib.in");
ofstream fout("aib.out");
int n, m, i, j, a[100005], t, x, y;
void update(int poz, int val)
{
    for(int i=poz; i<=n; i+=i&(-i))
        a[i]+=val;
}
int query(int poz)
{
    int sum=0;
    for(int i=poz; i>=1; i-=i&(-i))
        sum+=a[i];
    return sum;
}
int main()
{
    fin>>n>>m;
    for(i=1; i<=n; i++)
    {
        fin>>x;
        update(i, x);
    }
    while(m--)
    {
        fin>>t;
        if(t==0)
        {
            fin>>x>>y;
            update(x, y);
        }
        else
            if(t==1)
        {
            fin>>x>>y;
            fout<<query(y)-query(x-1)<<'\n';
        }
        else
        {
            fin>>x;
            int st=1;
            int dr=n;
            int poz=-1;
            while(st<=dr)
            {
                int mij=(st+dr)/2;
                if(query(mij)>=x)
                {
                    dr=mij-1;
                    if(query(mij)==x)
                    poz=mij;
                }
                else
                    st=mij+1;
            }
            fout<<poz<<'\n';
        }
    }
    return 0;
}