Cod sursa(job #2156492)

Utilizator NicuBaciuNicu Baciu NicuBaciu Data 8 martie 2018 19:23:18
Problema Arbori indexati binar Scor 30
Compilator cpp Status done
Runda Arhiva educationala Marime 1.5 kb
#include <fstream>
#include <stdio.h>

#define inc(x) ( x & -x )

using namespace std;

//ifstream fin("aib.in");
ofstream fout("aib.out");

int n, m;

int a[100002];
int din[100002];

FILE* f;

void read_data()
{
    fscanf(f, "%d %d", &n, &m);

    for(int i=1; i<=n; i++)
    {
        fscanf(f, "%d", &a[i]);
    }

    for(int i=1; i<=n; i++)
    {
        for(int j=i; j<=n; j+=inc(j))
            din[j]+=a[i];
    }
}

int prefsum_at(int x)
{
    int sum=0;

    for(int i=x; i>0; i-=inc(i))
        sum+=din[i];

    return sum;
}

int main()
{
    f=fopen("aib.in", "r");

    read_data();

    for(int i=1; i<=m; i++)
    {
        int op=-1;
        int x=0, y=0;

        fscanf(f, "%d", &op);

        if(op!=2)
        {
            fscanf(f, "%d %d", &x, &y);
        }
        else
        {
            fscanf(f, "%d", &x);
        }

        if(op==0)
        {
            for(int i=x; i<=n; i+=inc(i))
                din[i]+=y;
        }
        else if(op==1)
        {
            fout << prefsum_at(y) - prefsum_at(x-1) << '\n';
        }
        else if(op==2)
        {
            int s=0;

            for(int i=1; i<=n; i++)
            {
                if(prefsum_at(i)==x)
                {
                    fout << i << '\n';
                    break;
                }
                if(i==n && prefsum_at(i)!=x)
                    fout << "-1" << '\n';
            }
        }
    }

    return 0;
}