Cod sursa(job #2118438)

Utilizator Lazar_LaurentiuLazar Laurentiu Lazar_Laurentiu Data 30 ianuarie 2018 17:35:01
Problema Arbori indexati binar Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.96 kb
#include <iostream>
#include <fstream>
#define MAX 100001

using namespace std;

int n,m,sp[MAX],a,b,o;
int nsb(int nr){return nr^(nr&(nr-1));}
void update(int ind,int val){
  for(;ind<=n;ind+=nsb(ind))sp[ind]+=val;
}
int query(int ind){
  int ans=0;
  for(;ind>=1;ind-=nsb(ind))ans+=sp[ind];
  return ans;
}
int cautbin(int sum){
  int st=1,dr=n,mij;
  while(st<dr){
    mij=(st+dr)/2;
    if(query(mij)<sum)st=mij+1;
    else dr=mij;
  }
  if(query(st)==sum)return st;
  else return -1;
}

int main()
{
    ifstream f ("aib.in");
    ofstream g ("aib.out");
    f>>n>>m;
    for(int i=1;i<=n;i++){
      f>>a;
      update(i,a);
    }
    for(int i=1;i<=m;i++){
      f>>o;
      if(o==0){
        f>>a>>b;
        update(a,b);
      } else if(o==1){
        f>>a>>b;
        g<<query(b)-query(a-1)<<'\n';
      } else {
        f>>a;
        g<<cautbin(a)<<'\n';
      }
    }
    f.close ();
    g.close ();
    return 0;
}