Cod sursa(job #3224192)

Utilizator tudor_costinCostin Tudor tudor_costin Data 14 aprilie 2024 21:23:39
Problema Arbori indexati binar Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.27 kb
#pragma GCC target("sse4.2")
#include <fstream>

using namespace std;
ifstream cin("aib.in");
ofstream cout("aib.out");
const int Nmax=100005;
int aib[Nmax];
int lsb(int x)
{
    return(x^(x-1))&x;
}
void update(int a,int b,int n)
{
    for(int i=a;i<=n;i+=lsb(i))
    {
        aib[i]+=b;
    }
}
int query(int a)
{
    int sol=0;
    for(int i=a;i>0;i-=lsb(i))
    {
        sol=sol+aib[i];
    }
    return sol;
}
int bs(int a,int n)
{
    int k=__builtin_clz(n);
    int d=(1<<(31-k));
    int p=0;
    for(int i=d;i>0;i=i>>1)
    {
        if(p+i<=n && aib[p+i]<=a)
        {
            a=a-aib[p+i];
            p=p+i;
        }
    }
    if(a==0 && p!=0)
    {
        return p;
    }
    else return -1;
}
int main()
{

    int n,m;
    cin>>n>>m;
    for(int i=1;i<=n;i++)
    {
        int x;
        cin>>x;
        update(i,x,n);
    }
    int a,b,c;
    for(int i=1;i<=m;i++)
    {
        cin>>c;
        if(c==0)
        {
            cin>>a>>b;
            update(a,b,n);
        }
        if(c==1)
        {
            cin>>a>>b;
            cout<<query(b)-query(a-1)<<'\n';
        }
        if(c==2)
        {
            cin>>a;
            cout<<bs(a,n)<<'\n';
        }
    }
    return 0;
}