Cod sursa(job #2736913)

Utilizator AndreiD31Dragan Andrei AndreiD31 Data 4 aprilie 2021 10:32:06
Problema Arbori indexati binar Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.06 kb
#include <bits/stdc++.h>
#define ind(i) (i&(-i))

using namespace std;

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

int n,aib[100100];

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

int suma(int poz)
{
    int S=0;
    for(int i=poz;i>=1;i-=ind(i))
        S+=aib[i];
    return S;
}

int m,i,x,c,a,b,S,p,u,mij,pz;
int main()
{
    f>>n>>m;
    for(i=1;i<=n;i++)
    {
        f>>x;
        update(i,x);
    }
    for(i=1;i<=m;i++)
    {
        f>>c;
        if(c==0)
        {
            f>>a>>b;
            update(a,b);
        }
        else if(c==1)
        {
            f>>a>>b;
            g<<suma(b)-suma(a-1)<<'\n';
        }
        else
        {
            f>>a;
            p=1;u=n;pz=-1;
            while(p<=u)
            {
                mij=(p+u)/2;
                S=suma(mij);
                if(S==a){pz=mij;break;}
                else if(S>a)u=mij-1;
                else p=mij+1;
            }
            g<<pz<<'\n';
        }
    }
    return 0;
}