Cod sursa(job #2509303)

Utilizator VladMxPMihaila Vlad VladMxP Data 14 decembrie 2019 09:36:58
Problema Arbori indexati binar Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.04 kb
#include <iostream>
#include <fstream>
using namespace std;
ifstream fin("aib.in");
ofstream fout("aib.out");
int n,m,aib[100001],x,a,b,c;
void update(int x,int p)
{
    int i;
    for(i=p;i<=n;i+=(i&(-i)))
        aib[i]+=x;
}
int suma(int p)
{
    int i,s=0;
    for(i=p;i>0;i-=(i&(-i)))s+=aib[i];
    return s;
}
int caut(int a)
{
    int st=1,dr=n,m1;
    while(st<=dr)
    {
        m1=(st+dr)/2;
        int s=suma(m1);
        if(s==a)return m1;
        else
        {
            if(s>a)dr=m1-1;
            else st=m1+1;
        }
    }
    return -1;
}
int main()
{
    fin>>n>>m;
    for(int i=1;i<=n;i++)
    {
        fin>>x;
        update(x,i);
    }
    for(int i=1;i<=m;i++)
    {
        fin>>c;
        if(c==0)
        {
            fin>>a>>b;
            update(b,a);
        }
        else if(c==1)
        {
            fin>>a>>b;
            fout<<suma(b)-suma(a-1)<<'\n';
        }
        else
        {
            fin>>a;
            fout<<caut(a)<<'\n';
        }
    }
}