Cod sursa(job #2440339)

Utilizator iulianarsenoiuArsenoiu Iulian iulianarsenoiu Data 18 iulie 2019 10:57:29
Problema Arbori indexati binar Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.2 kb
#include <fstream>

using namespace std;
ifstream f("aib.in");
ofstream g("aib.out");
int n,m,a,b,aib[100005],v[100005],c,i;
int UB(int x)
{
    return (x&(-x));
}
void Add(int a,int b)
{
    for(int i=a;i<=n;i+=UB(i))
        aib[i]+=b;
}
int Sum(int x)
{
    int s=0;
    for(int i=x;i>=1;i-=UB(i))
        s+=aib[i];
    return s;
}
int cb(int x, int n)
{
    int st=1;
    int dr=n;
    int mij=0;
    int s=0;
    int p=0;
    while(st<=dr)
    {
        mij=(st+dr)/2;
        s=Sum(mij);
        if(s==x)
        {
            p=mij;
        }
        if(s>=x)
            dr=mij-1;
        else
            st=mij+1;
    }
    if(p==0)
        return -1;
    else
        return p;
}
int main()
{
    f>>n>>m;
    for(i=1;i<=n;i++)
        f>>v[i];
    for(i=1;i<=n;i++)
    {
        Add(i,v[i]);
    }
    for(i=1;i<=m;i++)
    {
        f>>c;
        if(c==0)
        {
            f>>a>>b;
            Add(a,b);
        }
        else if(c==1)
        {
            f>>a>>b;
            g<<Sum(b)-Sum(a-1)<<'\n';
        }
        else if(c==2)
        {
            f>>a;
            g<<cb(a,n)<<'\n';
        }
    }
    return 0;
}