Cod sursa(job #1960107)

Utilizator DragosCDragos Corleanca DragosC Data 10 aprilie 2017 10:48:29
Problema Arbori indexati binar Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.25 kb
#include <iostream>
#include <fstream>
#define zeros(x) ((x^(x-1))&x)
using namespace std;
int n,m;
int aib[100001];
void op0(int x, int q)
{
    for(int i=x; i<=n; i+=zeros(i))
        aib[i]+=q;
}
int Compute(int x)
{
    int sum=0;
    for(int i=x; i>0; i-=zeros(i))
        sum+=aib[i];
    return sum;
}
int op1(int a, int b)
{
    return Compute(b)-Compute(a-1);
}

int op2(int a, int st, int dr)
{
    if(st>dr)
        return -1;
    else if(st==dr)
    {
        if(Compute(st)==a)
            return st;
        else return -1;
    }

    int mij=(st+dr)/2;
    int x=Compute(mij);
    if(x==a)
        return mij;
    else if(x<a) return op2(a,mij+1,dr);
    else return op2(a,st,mij-1);
}


int main()
{
    ifstream f("aib.in");
    ofstream g("aib.out");
    f>>n>>m;
    int x;
    for(int i=1; i<=n; i++)
    {
        f>>x;
        op0(i,x);
    }
    int y,z;
    for(int i=1; i<=m; i++)
    {
        f>>x;
        if(x==0)
        {
            f>>y>>z;
            op0(y,z);
        }
        else if(x==1)
        {
            f>>y>>z;
            g<<op1(y,z)<<'\n';
        }
        else
        {
            f>>y;
            g<<op2(y,1,n)<<'\n';
        }
    }
    return 0;
}