Cod sursa(job #1985232)

Utilizator mateisoroSorodoc Matei mateisoro Data 27 mai 2017 11:04:09
Problema Arbori indexati binar Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.02 kb
#include <bits/stdc++.h>

using namespace std;
ifstream f("aib.in");
ofstream g("aib.out");
const int N=100010;
int n,m,A[N];
void update  (int p, int v)
{
    for(int i=p;i<=n;i+=(i&(-i)))
        A[i]+=v;
}
int suma  (int p)
{
    int s=0;
    for(int i=p;i>0;i-=(i&(-i)))
        s+=A[i];
    return s;
}
int main()
{
    f>>n>>m;
    for(int i=1;i<=n;i++)
    {
        int x;
        f>>x;
        update(i,x);
    }
    for(;m;m--)
    {
        int a,b,c;
        f>>c>>a;
        if(c==2)
        {
            int st=0,dr=n,mi;
            while(dr-st>1)
            {
                mi=(st+dr)/2;
                if(suma(mi)<a)
                    st=mi;
                else
                    dr=mi;
            }
            if(suma(dr)==a)
                g<<dr<<'\n';
            else
                g<<-1;
            continue;
        }
        f>>b;
        if(c==0)
            update(a,b);
        else
            g<<suma(b)-suma(a-1)<<'\n';
    }
    return 0;
}