Cod sursa(job #2803536)

Utilizator barbuantoniabarbu antonia elena barbuantonia Data 20 noiembrie 2021 10:34:32
Problema Arbori indexati binar Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.03 kb
#include <bits/stdc++.h>
#define ub(x)(x&(-x))
using namespace std;
ifstream f("aib.in");
ofstream g("aib.out");
int n,m,aib[100001],a,b,c,x;

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

int sum(int x)
{
    int s=0;
    for(int i=x; i>0; i-=ub(i))
        s+=aib[i];
    return s;
}

int cb(int a)
{
    int st,dr,mij;
    st=1;
    dr=n;
    while(st<=dr)
    {
        mij=(st+dr)/2;
        if(sum(mij)<a)st=mij+1;
        if(sum(mij)>a)dr=mij-1;
        if(sum(mij)==a)return mij;
    }
    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>>c;
        if(c==0)
        {
            f>>a>>b;
            update(a,b);
        }
        if(c==1)
        {
            f>>a>>b;
            g<<sum(b)-sum(a-1)<<'\n';
        }
        if(c==2)
        {
            f>>a;
            g<<cb(a)<<'\n';
        }
    }
    return 0;
}