Cod sursa(job #3030052)

Utilizator PatruMihaiPatru Mihai PatruMihai Data 17 martie 2023 14:29:17
Problema Arbori indexati binar Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.29 kb
#include <bits/stdc++.h>

using namespace std;

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

const int NMAX = 1e5 + 7;

int n, m;
vector<int> v(NMAX);

void update(int x, int t)
{
    for (int i = t; i <= n; i += i & (-i))
        v[i] += x;
}

int query(int t)
{
    int s = 0;

    for(int i = t; i > 0; i -= i & (-i))
    {
        s += v[i];
    }
    return s;
}

int BinarySearch(int x)
{
    int left = 1;
    int right = n;
    int ans = -1;

    while(left <= right)
    {
        int mid = (left + right) / 2;
        int sum = query(mid);

        if (sum == x)
            ans = mid;
        
        if (sum >= x)
            right = mid - 1;
        else
            left = mid + 1;

    }

    return ans;

}

int main()
{
    fin >> n >> m;

    for(int i = 1; i <= n; i++)
    {
        int x;
        fin >> x;
        update(x, i);
    }

    for(int i = 1; i <= m; i++)
    {
        int type;
        fin >> type;

        if(type == 0 || type == 1)
        {
            int a, b;
            fin >> a >> b;

            if (type == 0)
                update(b, a);
            else
                fout << query(b) - query(a - 1) << "\n";
        }
        else
        {
            int a;
            fin >> a;
            fout << BinarySearch(a) << "\n";
        }
    }

    return 0;
}