Cod sursa(job #1336361)

Utilizator bogdanboboc97Bogdan Boboc bogdanboboc97 Data 7 februarie 2015 17:20:14
Problema Arbori indexati binar Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.23 kb
#include <bits/stdc++.h>
#define bit(x) (-x)&x //2^(numarul de zerouri terminale din reprezentarea lui x)
using namespace std;
ifstream in("aib.in");
ofstream out("aib.out");
vector<int> aib;
int n,p;
void update(int pos,int x)
{
    for(int i=pos;i<=n;i+=bit(i))
        aib[i]+=x;
}
int qsum(int pos)//suma elementelor din intervalul [1,pos]
{
    int sum=0;
    for(int i=pos;i>0;i-=bit(i))
        sum+=aib[i];
    return sum;
}
int query(int x)//cautare binara
{
    int left=1,right=n;
    while(left<=right)
    {
        int mid=(left+right)/2;
        int sum=qsum(mid);
        if(sum==x)return mid;
        else if(sum>x)left=mid+1;
        else right=mid-1;
    }
    return -1;
}
int main()
{
    int m,pos,x,y,t;
    in>>n>>m;
    aib=vector<int>(n+1);
    for(p=1;p<=n;p*=2);
    for(int i=1;i<=n;i++)
    {
        in>>x;
        update(i,x);
    }
    for(;m;m--)
    {
        in>>t;
        if(t==0)
        {
            in>>pos>>x;
            update(pos,x);
        }
        else if(t==1)
        {
            in>>x>>y;
            out<<qsum(y)-qsum(x-1)<<'\n';
        }
        else{
            in>>x;
            out<<query(x)<<'\n';
        }
    }
    return 0;
}