Cod sursa(job #2393280)

Utilizator mjmilan11Mujdar Milan mjmilan11 Data 31 martie 2019 11:38:14
Problema Arbori indexati binar Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.31 kb
#include <bits/stdc++.h>
#define p(x) (x & -x)

using namespace std;

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

const int INF = (1<<29);
const int NMAX = 100005;
int aib[NMAX];
int n,m;

void update(int poz,int val)
{
    for(int i=poz;i<=n;i+=p(i))
        aib[i]+=val;
}

int query(int poz)
{
    int sum=0;
    for(int i=poz;i>=1;i-=p(i))
        sum+=aib[i];
    return sum;
}

int find_poz(int a)
{
    int ind=0;
    int poz=INF,k=0;
    while(poz!=0)
    {
        if(ind+poz<=n)
        {
            if(k+aib[ind+poz]<=a)
            {
                k+=aib[ind+poz];
                ind+=poz;
                if(k==a) return ind;
            }
        }
        poz/=2;
    }
    return -1;
}

int main()
{
    fin >> n >> m;
    int x;
    for(int i=1;i<=n;i++)
    {
        fin >> x;
        update(i,x);
    }
    int a,b,operatie;
    for(int i=1;i<=m;i++)
    {
        fin >> operatie;
        if(operatie==0)
        {
            fin >> a >> b;
            update(a,b);
        }
        else if(operatie==1)
        {
            fin >> a >> b;
            fout << query(b)-query(a-1) << '\n';
        }
        else if(operatie==2)
        {
            fin >> a;
            fout << find_poz(a) << '\n';
        }
    }
    return 0;
}