Cod sursa(job #3276376)

Utilizator Dia3141Costea Diana Stefania Dia3141 Data 13 februarie 2025 14:55:22
Problema Arbori indexati binar Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.93 kb
#include <fstream>
#define nmax (int)(1e5+1)
using namespace std;
ifstream cin("aib.in");
ofstream cout("aib.out");
int n,m,task,a,b,aib[nmax];
void update(int p,int x){
    for(;p<=n;p+=(-p)&p)
        aib[p]+=x;
}
int query(int p){
    int r=0;
    for(;p>0;p-=(-p)&p)
        r+=aib[p];
    return r;
}
int cb(){
    int st=1,dr=n,p=-1;
    while(st<=dr){
        int mid=(st+dr)/2,s=query(mid);
        if(s>=a){
            if(s==a)
                p=mid;
            dr=mid-1;
        }else
            st=mid+1;
    }
    return p;
}
signed main()
{
    cin>>n>>m;
    for(int i=1;i<=n;i++){
        cin>>a;
        update(i,a);
    }
    while(m--){
        cin>>task>>a;
        if(task==2){
            cout<<cb()<<'\n';
            continue;
        }
        cin>>b;
        if(task==0)
            update(a,b);
        else
            cout<<query(b)-query(a-1)<<'\n';
    }
    return 0;
}