Cod sursa(job #1740278)

Utilizator antracodRadu Teodor antracod Data 11 august 2016 12:59:03
Problema Datorii Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.29 kb
#include <iostream>
#include <fstream>

using namespace std;

ifstream in("datorii.in");
ofstream out("datorii.out");

int aib[100001];
int n,n2;

int query(int x)
{
    int sol=0;
    for(int i=x;i>0;i=(i&(i-1)))
    {
        sol+=aib[i];
    }
    return sol;
}

void update(int x,int y)
{
    for(int i=x;i<=n;i=2*i-(i&(i-1)))
    {
        aib[i]-=y;
    }

}

int caut(int x)
{
    int sol=0,poz=0;

    for(int i=n2;i>0;i=i/2)
    {
        if(poz+i<=n && sol+aib[poz+i]<=x)
        {
            sol=sol+aib[poz+i];
            poz=poz+i;
        }
    }
    if(sol==x)
        return poz;
    else
        return -1;
}

int main()
{
    int m;
    in>>n>>m;

    for(int i=1;i<=n;i++)
    {
        in>>aib[i];
        aib[i]+=query(i-1)-query(i&(i-1));
    }

    for(n2=1;n2<=n;n2=n2*2)
    {}
    n2=n2/2;

    for(int i=1;i<=m;i++)
    {
        int op;
        in>>op;
        if(op==0)
        {
            int x,y;
            in>>x>>y;
            update(x,y);
        }
        else if(op==1)
        {
            int x,y;
            in>>x>>y;
            out<<query(y)-query(x-1)<<'\n';
        }
        else
        {
            int x;
            in>>x;
            out<<caut(x)<<'\n';
        }
    }

}