Cod sursa(job #1247547)

Utilizator akaprosAna Kapros akapros Data 22 octombrie 2014 22:39:27
Problema Arbori indexati binar Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.24 kb
#include<cstdio>
#include<algorithm>
using namespace std;
int n,i,j,nr,k,a,b,m;
int AIB[100005];
void ADD(int x,int y)
{
    int i;
    for (i=x;i<=n;i=i+(i&(-i)))
    AIB[i]+=y;
}
int SUM(int x)
{
    int i,s=0;
    for (i=x;i>=1;i=i-(i&(-i))) s=s+AIB[i];
    return s;
}
int cb(int x)
{
    int s,st,dr,m;
    st=1; dr=n;
    s=SUM(1);
    if (s>x) return -1;
    if (s==x) return 1;
    s=SUM(n);
    if (s<x) return -1;
    if (s==x) return n;
    while (st<=dr)
    {
        m=(st+dr)/2;
        s=SUM(m);
        if (s==x) return m;
        if ((s<x)&&(SUM(m+1)>x)) return -1;
        if (s<x) st=m+1;
        else dr=m-1;
    }
}
int main()
{
    freopen("aib.in","r",stdin);
    freopen("aib.out","w",stdout);
    scanf("%d %d",&n,&m);
    for (i=1;i<=n;i++)
    {
        scanf("%d",&nr);
        ADD(i,nr);
    }
    while (m--)
    {
        scanf("%d",&nr);
        if (nr==0)
        {
            scanf("%d %d",&a,&b);
            ADD(a,b);
        }
        if (nr==1)
        {
            scanf("%d %d",&a,&b);
            printf("%d\n",SUM(b)-SUM(a-1));
        }
        if (nr==2)
        {
            scanf("%d",&a);
            printf("%d\n",cb(a));
        }
    }
    return 0;
}