Cod sursa(job #1988687)

Utilizator Daria09Florea Daria Daria09 Data 4 iunie 2017 11:44:28
Problema Arbori indexati binar Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.14 kb
#include <iostream>
#include <fstream>
#define dim 10000005
using namespace std;
ifstream f("aib.in");
ofstream g("aib.out");
int n,m,arb[dim];
void update(int pos,int val)
{
    for(int i=pos; i<=n; i+=(i&-i))
        arb[i]+=val;
}
int query(int val)
{
    int ans=0;
    for(int j=val; j>=1; j-=(j&-j))
        ans+=arb[j];
    return ans;
}
int Search(int val)
{
    int st=1,dr=n,mij;
    while(st<=dr)
    {
        mij=(st+dr)/2;
        int ans=query(mij);
        if(val==ans)
            return mij;
        else if(val<ans)
            dr=mij-1;
        else
            st=mij+1;
    }
    return -1;
}
int main()
{
    f>>n>>m;
    for(int i=1; i<=n; i++)
    {
        int x;
        f>>x;
        update(i,x);
    }
    int caz,a,b;
    for(int i=1; i<=m; i++)
    {
        f>>caz;
        if(caz==0)
        {
            f>>a>>b;
            update(a,b);
        }
        else if(caz==1)
        {
            f>>a>>b;
            g<<query(b)-query(a-1)<<'\n';
        }
        else if(caz==2)
        {
            f>>a;
            g<<Search(a)<<'\n';
        }
    }
    return 0;
}