Cod sursa(job #854205)

Utilizator enedumitruene dumitru enedumitru Data 12 ianuarie 2013 21:55:21
Problema Arbori indexati binar Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.09 kb
#include <cstdio>
#define slb(x) (x & -x)
using namespace std;
int N, M, Arb[100001];
void Update(int k,int x)
{
    for ( ; k<=N; k += slb(k)) Arb[k] += x;
}
int Query(int k)
{
    int s=0;
    for ( ; k>0; k -= slb(k)) s += Arb[k];
    return s;
}
int Search(int val)
{
    int i, step;
    for ( step = 1; step < N; step <<= 1 );
    for( i = 0; step; step >>= 1 )
         if( i + step <= N && val >= Arb[i+step] )
            {
                i += step, val -= Arb[i];
                if ( !val ) return i;
            }
    return -1;
}
int main()
{   int K, X, Y;
    freopen("aib.in","r",stdin);
    freopen("aib.out","w",stdout);
    scanf("%d%d", &N, &M);
    for ( int i = 1; i <= N; ++i )
        scanf("%d", &Y), Update(i,Y);
    while(M--)
    {
        scanf("%d", &K);
        if ( K < 2 )
        {
             scanf("%d%d", &X, &Y);
             if ( K )  printf("%d\n", Query(Y)-Query(X-1)); else  Update(X,Y);
        }
        else
        {
            scanf("%d", &X);
            printf("%d\n", Search(X));
        }
    }
    return 0;
}