Cod sursa(job #2831583)

Utilizator DordeDorde Matei Dorde Data 11 ianuarie 2022 18:29:14
Problema Arbori indexati binar Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.33 kb
#include<bits/stdc++.h>
#define z(x) ((x)&(-x))
using namespace std;
ifstream fin("aib.in");
ofstream fout("aib.out");
int const N = 1e5 + 3;
int n , m , op , a , b;
class aib{
public:
    int v[N];
    aib(){
        fill(v , v + N , 0);
    }
    void add(int p , int x){
        for(int i = p ; i <= n ; i += z(i))
            v[i] += x;
    }
    int sum(int p){
        int r = 0;
        for(int i = p ; i ; i -= z(i))
            r += v[i];
        return r;
    }
    int solve(int a){
        int pas = (1 << 16) , r = 0;
        while(pas){
            if(pas + r <= n && v[pas + r] <= a){
                a -= v[pas + r];
                r += pas;
            }
            pas >>= 1;
        }
        if(a == 0 && r)
            return r;
        return -1;
    }
}t;
int main()
{
    fin >> n >> m;
    for(int i = 1 ; i <= n ; ++ i){
        fin >> a;
        t.add(i , a);
    }
    for(int i = 1 ; i <= m ; ++ i){
        fin >> op >> a;
        switch(op){
            case 0 :
                fin >> b;
                t.add(a , b);
                break;
            case 1:
                fin >> b;
                fout << t.sum(b) - t.sum(a - 1) << '\n';
                break;
            case 2:
                fout << t.solve(a) << '\n';
        }
    }
    return 0;
}