Cod sursa(job #2297329)

Utilizator AlexToveAlexandru Toader AlexTove Data 5 decembrie 2018 18:48:50
Problema Arbori indexati binar Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.22 kb
#include <bits/stdc++.h>
#define zeroes(x) (x&(-x))
using namespace std;

ifstream fin("aib.in");
ofstream fout("aib.out");

int aib[100001];
int n, m, cerinta, x, a, b, poz;

inline void update(int poz, int x)
{
    for(int i=poz; i<=n; i=i+zeroes(i))
        aib[i]=aib[i]+x;
}

inline int querry(int poz)
{
    int sum=0;
    for(int i = poz; i>0; i=i-zeroes(i))
        sum=sum + aib[i];
    return sum;
}

inline int search(int x)
{
    int st=1;
    int dr=n;
    while(st<=dr)
    {
        int m=(st+dr)/2;
        int sum=querry(m);
        if(sum==x)
            return m;
        if(sum>x)
            dr=m-1;
        else
            st=m+1;
    }
    return -1;
}

int main()
{
    fin>>n>>m;
    for(int i=1; i<=n; i++)
    {
        fin>>x;
        update(i, x);
    }
    for(int i=1; i<=m; i++)
    {
        fin>>cerinta;
        if(cerinta==0)
        {
            fin>>poz>>x;
            update(poz, x);
        }
        else if(cerinta==1)
        {
            fin>>a>>b;
            fout<<querry(b)-querry(a-1)<<"\n";
        }
        else if(cerinta==2)
        {
            fin>>x;
            fout<<search(x)<<"\n";
        }
    }
    return 0;
}