Cod sursa(job #2750648)

Utilizator Luca_Andrei1Andrei Luca MIhai Luca_Andrei1 Data 12 mai 2021 17:41:07
Problema Arbori indexati binar Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.27 kb
#include <fstream>

using namespace std;
int aib[100005];
int n;
void update(int poz, int val)
{
    for(; poz<=n; poz+=(poz ^(poz & (poz-1))))
        aib[poz]+=val;
}
int query(int poz)
{
    int sum=0;
    for(; poz>=1; poz-=(poz^(poz&(poz-1))))
        sum+=aib[poz];
    return sum;
}
ifstream cin("aib.in");
ofstream cout("aib.out");
int main()
{
    int m,i,a,b,op,st,dr,med,last,x;
    cin>>n>>m;
    for(i=1;i<=n;i++)
    {
        cin>>a;
        update(i,a);
    }
    for(i=1;i<=m;i++)
    {
        cin>>op>>a;
        if(op==0)
        {
            cin>>b;
            update(a,b);
        }
        else if(op==1)
        {
            cin>>b;
            cout<<query(b)-query(a-1)<<"\n";
        }
        else  if(op==2)
        {
            st=1;
            dr=n;
            last=-1;
            while(st<=dr)
            {
                med=(st+dr)/2;
                x=query(med);
                if(x<a)
                    st=med+1;
                else
                {
                        last=med;
                        dr=med-1;

                }
            }
            if(last!=-1 && query(last)!=a)
                last=-1;
            cout<<last<<"\n";
        }
    }
    return 0;
}