Cod sursa(job #3176014)

Utilizator paull122Paul Ion paull122 Data 26 noiembrie 2023 17:11:38
Problema Arbori indexati binar Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.62 kb
#include <bits/stdc++.h>

using namespace std;
typedef long long int ll;
#define MOD 666013


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

int a[100001];
int n,q;
int stot;
void update(int l,int v)
{
    stot += v;
    for(int i=l;i<=n;i+=(i&-i))
    {
        a[i]+=v;
    }
}
int query(int x)
{
    int res=0;
    for(int i=x;i>=1;i-=(i&-i))
    {
        res += a[i];
    }
    return res;
}
int main()
{
    fin >> n >> q;
    for(int i=1;i<=n;i++)
    {
        fin >> a[i];
    }
    for(int i=1;i<=n;i++)
    {
        if(i+(i&-i) <= n)
        {
            a[i+(i&-i)]+=a[i];
        }
    }
    while(q--)
    {
        int t,l,r;
        fin >> t;
        if(t==0)
        {
            fin >> l >> r;
            update(l,r);
        }
        if(t==1)
        {
            fin >> l >> r;
            fout << query(r)-query(l-1) << "\n";
        }
        if(t==2)
        {
           fin >> l;
           bool found=0;
           int sum=0,pos=0;
           for(int step=0;step<=18 && !found;step++)
           {
               if(pos + (1<<step) <= n)
               {
                    if(l<=sum+a[pos+(1<<step)])
                    {
                        sum += a[pos+(1<<step)];
                        pos += 1 << step;
                        if(sum==l)
                        {
                            fout << pos << '\n';
                            found=1;
                        }
                    }
               }
           }
           if(!found)
           {
               fout << "-1\n";
           }
        }
    }
}