Cod sursa(job #2620863)

Utilizator BogdanRuleaBogdan Rulea BogdanRulea Data 29 mai 2020 19:44:22
Problema Arbori indexati binar Scor 40
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.29 kb
#include <fstream>

using namespace std;
#define f "aib"
ifstream cin(f".in");
ofstream cout(f".out");
int a[100001],n,m,x,y,cond,k;
int c,s;
void update(int poz,int val)
{
    c=0;
    while(poz<=n)
    {
        a[poz]+=val;
        while(!(poz & (1<<c)))
            c++;
        poz+=(1<<c);
        c++;
    }

}
int query(int poz)
{
    c=0,s=0;
    while(poz>0)
    {
        s+=a[poz];
        while(!(poz & (1<<c)))
            c++;
        poz-=(1<<c);
        c++;
    }
    return s;
}
int Search_k(int val)
{
    int ans,i;
    for(ans=1;ans<=n;ans<<=1);
    for(i=0;ans;ans>>=1)
    {
        if(i+ans<=n && a[i+ans]<=val)
        {
            i+=ans;
            val-=a[i];
            if(!val)
                return i;
        }
    }
    return -1;
}
int main()
{
    cin>>n>>m;
    for(int i=1; i<=n; i++)
    {
        cin>>x;
        update(i,x);
    }
    for(int i=1;i<=m;i++)
    {
        cin>>cond;
        if(cond==0)
        {
            cin>>x>>y;
            update(x,y);
        }
        else if(cond==1)
        {
            cin>>x>>y;
            cout<<query(y)-query(x-1)<<endl;
        }
        else
        {
            cin>>k;
            cout<<Search_k(k)<<endl;
        }
    }
        return 0;
}