Cod sursa(job #2669553)

Utilizator D4R1U5Sava Darius D4R1U5 Data 7 noiembrie 2020 11:18:14
Problema Arbori indexati binar Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.03 kb
#include <bits/stdc++.h>
#define ub(x) (x&(-x))
#define nmax 100005
using namespace std;
ifstream f("aib.in");
ofstream g("aib.out");
int v[nmax],aib[nmax],n,m,c,x,y;
void add(int x,int val)
{
    for(int i=x;i<=n;i+=ub(i))aib[i]+=val;
}
int sum(int x)
{
    int s=0;
    for(int i=x;i>0;i-=ub(i))s+=aib[i];
    return s;
}
int cautbin(int x)
{
    int st=1,dr=n,poz=-1;
    while(st<=dr && poz==-1)
    {
        int mij=(st+dr)/2;
        int s=sum(mij);
        if(s==x)poz=mij;
        else if(s>x)dr=mij-1;
        else st=mij+1;
    }
    return poz;
}
int main()
{
    f>>n>>m;
    for(int i=1;i<=n;i++)
    {
        f>>v[i];
        add(i,v[i]);
    }
    for(int i=1;i<=m;i++)
    {
        f>>c;
        if(c==0)
        {
            f>>x>>y;
            add(x,y);
        }
        else if(c==1)
        {
            f>>x>>y;
            g<<sum(y)-sum(x-1)<<'\n';
        }
        else
        {
            f>>x;
            g<<cautbin(x)<<'\n';
        }
    }
    return 0;
}