Cod sursa(job #693715)

Utilizator Ast09Stoica Anca Ast09 Data 27 februarie 2012 16:04:04
Problema Arbori indexati binar Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.43 kb
#include <fstream>
using namespace std;
ifstream f("aib.in");
ofstream g("aib.out");

int m,n,v[100005],op,a,b;
int p2[]={1 , 2 , 4 , 8 , 16 , 32 , 64 , 128 , 256 , 512 , 1024 , 2048 , 4096 , 8192 , 16384 , 32768 , 65536 , 131072 , 262144 , 524288 , 1048576 , 2097152 , 4194304 , 8388608 , 16777216 , 33554432 , 67108864 , 134217728 , 268435456 , 536870912 , 1073741824};

void update(int i , int x)
{
    int bn=0;
    while(i<=n)
    {
        v[i]=v[i]+x;
        while((i&p2[bn])==0) bn++;
        i=i+p2[bn];
        bn++;
    }
}

int suma( int st, int dr)
{
    //if(b>n) {g<<-2; return -9;}
    int s2=0,s1=0,bn=0;
    while(dr>0)
    {
        s1=s1+v[dr];
        while((dr&p2[bn])==0) bn++;
        dr=dr-p2[bn];
        bn++;
    }
    st--;
    bn=0;
    while(st>0)
    {
        s2=s2+v[st];
        while((st&p2[bn])==0) bn++;
        st=st-p2[bn];
        bn++;
    }

    return s1-s2;
}

int poz(int x)
{
    int k=1;
    while(suma(1,k)!=x) k++;
    return k;
}

int main()
{
    int i,y,op;
    f>>n>>m;
    for(i=1;i<=n;i++)
    {
        f>>y;
        update(i,y);
    }
    for(i=1;i<=m;i++)
    {
        f>>op;
        switch(op)
        {
            case 0: f>>a>>b; update(a,b); break;
            case 1: f>>a>>b; g<<suma(a,b)<<'\n'; break;
            case 2: f>>a; g<<poz(a)<<'\n'; break;
        }
    }


    f.close();
    g.close();
    return 0;
}