Cod sursa(job #3150978)

Utilizator adelinapetreAdelina Petre adelinapetre Data 19 septembrie 2023 11:46:43
Problema Arbori indexati binar Scor 30
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.11 kb
#include <fstream>
#include <vector>
using namespace std;
ifstream cin("aib.in");
ofstream cout("aib.out");
vector<int> bit(100005, 0);
int v[100005];
int n;
void update(int i, int val)
{
    while(i<=n)
    {
        bit[i]+=val;
        i+=i&(-i);
    }
}
int prefix(int i)
{
    int sum=0;
    while(i>0)
    {
        sum+=bit[i];
        i-=i&(-i);
    }
    return sum;
}
int rangesum(int i, int j)
{
    return prefix(j)-prefix(i-1);
}
int main()
{
    int i,m,a,b,val,j;
    cin>>n>>m;
    for(i=1; i<=n; i++)
    {
        cin>>v[i];
        update(i,v[i]);
    }
    for(i=1; i<=m; i++)
    {
        cin>>val;
        if(val<2)
        {
            cin>>a>>b;
            if(val==0)
                update(a,b);
            else cout<<rangesum(a,b)<<'\n';
        }
        else
        {
            cin>>a;
            for(j=1; j<=n; j++)
                if(rangesum(1,j)==a)
                {
                    cout<<j<<'\n';
                    break;
                }
            if(j==n+1)
                cout<<-1<<'\n';
        }
    }
    return 0;
}