Cod sursa(job #2442211)

Utilizator filiptudose2007Tudose Filip filiptudose2007 Data 23 iulie 2019 12:15:07
Problema Arbori indexati binar Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.09 kb
#include <bits/stdc++.h>
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,dr=n,mij=0,s=0,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;
}