Cod sursa(job #1760879)

Utilizator B_RazvanBaboiu Razvan B_Razvan Data 21 septembrie 2016 14:07:09
Problema Arbori indexati binar Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.47 kb
#include <iostream>
#include <cstdio>
#include <cmath>

using namespace std;

int n, m, a[100005];

int zero(int t)
{
    int q=(t^(t-1))&t;
    return q;
}

void adaugare(int x, int y)
{
    for(int i=x; i<=n; i+=zero(i))
        a[i]+=y;
}

int determinareSuma(int x, int y)
{
    int s1=0, s2=0;
    for(int i=y; i>=1; i-=zero(i))
        s1+=a[i];
    for(int i=x-1; i>=1; i-=zero(i))
        s2+=a[i];
    return (s1-s2);
}

int determinarePozitieMinima(int x)
{
    int st=1, dr=n;
    while(st<=dr)
    {
        int mij=(st+dr)/2, suma=determinareSuma(1, mij);
        if(suma==x)
            return mij;
        if(suma>x)
            dr=mij-1;
        else
            st=mij+1;
    }
    return -1;
}

void citire()
{
    scanf("%d %d", &n, &m);
    for(int i=1; i<=n; ++i)
    {
        int x;
        scanf("%d", &x);
        adaugare(i, x);
    }
    for(int i=1; i<=m; ++i)
    {
        int c, x, y;
        scanf("%d", &c);
        if(c==0)
        {
            scanf("%d %d", &x, &y);
            adaugare(x, y);
        }
        else if(c==1)
        {
            scanf("%d %d", &x, &y);
            printf("%d\n", determinareSuma(x, y));
        }
        else if(c==2)
        {
            scanf("%d", &x);
            printf("%d\n", determinarePozitieMinima(x));
        }
    }
}

int main()
{
    freopen("aib.in", "r", stdin);
    freopen("aib.out", "w", stdout);
    citire();
    return 0;
}