Cod sursa(job #2601307)

Utilizator betybety bety bety Data 14 aprilie 2020 12:22:07
Problema Arbori indexati binar Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.18 kb
#include <fstream>
using namespace std;
ifstream cin("aib.in");
ofstream cout("aib.out");
const int lim=1e5+3;
int n,m,tip,a,b;
int tree[lim];
void add(int k,int x)
{
    while(k<=n)
    {
        tree[k]+=x;
        k+=k&-k;
    }
}
int sum(int k)
{
    int s=0;
    while(k>=1)
    {
        s+=tree[k];
        k-=k&-k;
    }
    return s;
}
int bs(int x)
{
    if(x<sum(1))
        return -1;
    int l=1,r=n,med;
    while(l<r)
    {
        med=(l+r)/2;
        int s=sum(med);
        if(s>x)
            r=med-1;
        else if(s<x)
            l=med+1;
        else r=med;
    }
    if(x==sum(l))
        return l;
    return -1;
}
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0),cout.tie(0);
    cin>>n>>m;
    for(int i=1;i<=n;++i)
        cin>>a,add(i,a);
    for(int i=1;i<=m;++i)
    {
        cin>>tip;
        if(tip==0)
        {
            cin>>a>>b;
            add(a,b);
        }
        else if(tip==1)
        {
            cin>>a>>b;
            cout<<sum(b)-sum(a-1)<<'\n';
        }
        else
        {
            cin>>a;
            cout<<bs(a)<<'\n';
        }
    }
    return 0;
}