Cod sursa(job #2296715)

Utilizator PopeangaMihneaPopeanga Mihnea- Stefan PopeangaMihnea Data 4 decembrie 2018 22:45:47
Problema Arbori indexati binar Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.14 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, op, x, a, b, idx;

inline void add(int idx, int x)
{
    for(int i=idx; i<=n; i=i+zeroes(i))
        AIB[i]=AIB[i]+x;
}

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

inline int caut(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;
        add(i, x);
    }
    for(int i=1; i<=m; ++i)
    {
        fin>>op;
        if(op==0)
        {
            fin>>idx>>x;
            add(idx, x);
        }
        else if(op==1)
        {
            fin>>a>>b;
            fout<<querry(b)-querry(a-1)<<"\n";
        }
        else if(op==2)
        {
            fin>>x;
            fout<<caut(x)<<"\n";
        }
    }
    return 0;
}