Cod sursa(job #2350001)

Utilizator radurotaruRotaru Radu Stefan radurotaru Data 20 februarie 2019 22:14:01
Problema Arbori indexati binar Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.23 kb
#include <fstream>

using namespace std;

ifstream f("aib.in");
ofstream g("aib.out");

int BITree[100005],n,x,m,a,b;

int getSum(int q)
{
    int s=0;
    while(q)
    {
        s=s+BITree[q];
        q-=q &(-q);
    }
    return s;
}
void update(int q, int val)
{
    while(q<= n)
    {
        BITree[q]+=val;
        q+=q &(-q);
    }
}
int Search(int val)
{
    int q;
    for (q=1; q<n; q <<= 1);
    {
        for(int i=0; q; q >>=1)
        {
            if( i+q<=n)
            {
                if(val>=BITree[i+q])
                {
                    i+=q;
                    val-=BITree[i];
                    if(!val)
                        return i;
                }
            }
        }
    }
    return -1;
}
int main()
{
    f>>n>>m;
    for(int i=1; i<=n; i++)
    {
        f>>x;
        update(i, x);
    }

    for(int i=1; i<=m; i++)
    {
        f>>x;
        if(x==0)
        {
            f>>a>>b;
            update(a, b);
        }
        if(x==1)
        {
            f>>a>>b;
            g<<getSum(b)-getSum(a-1)<<'\n';
        }
        if(x==2)
        {
            f>>a;
            g<<Search(a)<<'\n';
        }
    }
    return 0;
}