Cod sursa(job #3211574)

Utilizator Robert_NicuNicu Robert Cristian Robert_Nicu Data 9 martie 2024 15:27:23
Problema Arbori indexati binar Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.08 kb
#include <bits/stdc++.h>
#define DIM 100001
using namespace std;

ifstream fin("aib.in");
ofstream fout("aib.out");

int n, q, task, a, b;
int i, j;
int v[DIM], aib[DIM];

void update(int poz, int val){
    for(int i=poz; i<=n; i+=(i&-i))
        aib[i]+=val;
}

int query(int poz){
    int ans=0;
    for(int i=poz; i>0; i-=(i&-i))
        ans+=aib[i];
    return ans;
}

int cb(int val){
    int st=1, dr=n;
    while(st<=dr){
        int mij=(st+dr)/2;
        int poz=query(mij);
        if(poz<val)
            st=mij+1;
        if(poz>val)
            dr=mij-1;
        if(poz==val)
            return mij;
    }
    return -1;
}

int main(){
    fin>>n>>q;
    for(i=1; i<=n; i++){
        fin>>v[i];
        update(i, v[i]);
    }

    while(q--){
        fin>>task;
        if(task==0){
            fin>>a>>b;
            update(a, b);
        }
        if(task==1){
            fin>>a>>b;
            fout<<query(b)-query(a-1)<<"\n";
        }
        if(task==2){
            fin>>a;
            fout<<cb(a)<<"\n";
        }
    }
}