Cod sursa(job #2182863)

Utilizator Alex_AeleneiAlex Aelenei Ioan Alex_Aelenei Data 22 martie 2018 17:54:33
Problema Arbori indexati binar Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.29 kb
#include <cstdio>
#include <iostream>
using namespace std;
int v[100005];
int aib[100005];
int n;
void update(int poz,int val)
{
    for( ; poz<=n; poz+=poz&-poz)
        aib[poz]+=val;
}
int query(int poz)
{
    int s=0;
    for( ; poz>0; poz-=poz&-poz)
        s+=aib[poz];
    return s;
}
int bs(int val)
{
    int st=1,dr=n,med,b,last=-1;
    while(st<=dr)
    {
        med=(st+dr)/2;
        b=query(med);
        if(b==val)
        {
            last=med;
            dr=med-1;
        }
        else if(val>b)
            st=med+1;
        else
            dr=med-1;
    }
    return last;
}
int main()
{
    freopen("aib.in","r",stdin);
    freopen("aib.out","w",stdout);
    int m,i,c,a,b,x;
    scanf("%d%d",&n,&m);
    for(i=1; i<=n; ++i)
    {
        scanf("%d",&x);
        update(i,x);
    }
    for(i=1; i<=m; ++i)
    {
        scanf("%d",&c);
        if(c==0)
        {
            scanf("%d%d",&a,&b);
            update(a,b);
        }
        else if(c==1)
        {
            scanf("%d%d",&a,&b);
            if(a>b)
                swap(a,b);
            printf("%d\n",query(b)-query(a-1));
        }
        else if(c==2)
        {
            scanf("%d",&a);
            printf("%d\n",bs(a));
        }
    }
    return 0;
}