Cod sursa(job #2158933)

Utilizator valentinoMoldovan Rares valentino Data 10 martie 2018 17:14:33
Problema Arbori indexati binar Scor 70
Compilator cpp Status done
Runda Arhiva educationala Marime 1.4 kb
#include <iostream>
#include <fstream>
#define zero(x) x
using namespace std;

ifstream f("aib.in");
ofstream g("aib.out");

const int NMax = 1e5 + 5;
int n, q, query, aib[NMax];

inline void Update( int poz, int val)
{
    for(int i = poz; i <= n; i += (i & (-i)))
        aib[ i ] += val;
}

inline int Query(int poz)
{
    int sum = 0;
    for(int i = poz; i; i -= (i & (-i)))
        sum += aib[ i ];
    return sum;
}

inline int Binary_Search( int val)
{
    int m, st = 1, dr = n, sum, minn = n + 1;
    while(st <= dr)
    {
        m = (st + dr) >> 1;
        sum = Query( m );
        if(sum == val)
        {
            minn = min(m, minn);
            dr = m - 1;
        }
        else if(sum > val)
            dr = m - 1;
        else
            st = m + 1;
    }
    if(minn != n + 1) return minn;
    return -1;
}

int main()
{
    int x, poz, val,a ,b;
    f >> n >> q;
    for(int i = 1; i <= n; ++i)
    {
        f >> x;
        Update(i, x);
    }
    for(int i = 1; i <= q; ++i)
    {
        f >> query;
        if(!query)
        {
            f >> poz >> val;
            Update(poz, val);
        }
        else if(query == 1)
        {
            f >> a >> b;
            g << Query( b ) - Query( a - 1 ) << '\n';
        }
        else
        {
            f >> a;
            g << Binary_Search( a ) << '\n';
        }
    }
}