Cod sursa(job #2300860)

Utilizator cyg_vladioanBirsan Vlad cyg_vladioan Data 12 decembrie 2018 10:50:01
Problema Arbori indexati binar Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.22 kb
#include <cstdio>
using namespace std;
int aib[100005], n;
void update(int poz, int val)
{
    for( ; poz <= n ; poz = poz + (poz & -poz))
        aib[poz] = aib[poz] + val;
}
int query(int poz)
{
    int suma = 0;
    for( ; poz > 0 ; poz = poz - (poz & -poz))
        suma = suma + aib[poz];
    return suma;
}
int bs(int k)
{
    int st, dr, med;
    st = 1;
    dr = n;
    while(st <= dr)
    {
        med = (st + dr) / 2;
        if(query(med) == k)
            return med;
        else if(query(med) < k)
            st = med + 1;
        else
            dr = med - 1;
    }
    return -1;
}
int main()
{
    freopen("aib.in", "r", stdin);
    freopen("aib.out", "w", stdout);
    int m, q, a, b, i, x;
    scanf("%d%d", &n, &m);
    for(i = 1 ; i <= n ; i ++)
    {
        scanf("%d", &x);
        update(i, x);
    }
    for(i = 1 ; i <= m ; i ++)
    {
        scanf("%d%d", &q, &a);
        if(q == 0)
        {
            scanf("%d", &b);
            update(a, b);
        }
        else if(q == 1)
        {
            scanf("%d", &b);
            printf("%d\n", query(b) - query(a - 1));
        }
        else
            printf("%d\n", bs(a));
    }
    return 0;
}