Cod sursa(job #1425338)

Utilizator alexandra_udristoiuUdristoiu Alexandra Maria alexandra_udristoiu Data 27 aprilie 2015 12:39:49
Problema Arbori indexati binar Scor 100
Compilator cpp Status done
Runda pregatire-lot-aib Marime 1.36 kb
#include<fstream>
using namespace std;
int n, m, i, t, a, b, p, u, mid;
int v[100003];
ifstream fin("aib.in");
ofstream fout("aib.out");
void update(int x, int val){
    for(; x <= n; x += (x & -x)){
        v[x] += val;
    }
}
int query(int x){
    int sum = 0;
    for(; x >= 1; x -= (x & -x)){
        sum += v[x];
    }
    return sum;
}
int main(){
    fin>> n >> m;
    for(i = 1; i <= n; i++){
        fin>> a;
        update(i, a);
    }
    for(i = 1; i <= m; i++){
        fin>> t;
        if(t == 0){
            fin>> a >> b;
            update(a, b);
        }
        else{
            if(t == 1){
                fin>> a >> b;
                p = query(a - 1);
                u = query(b);
                fout<< u - p <<"\n";
            }
            else{
                fin>> a;
                p = 1;
                u = n;
                while(p <= u){
                    mid = (p + u) / 2;
                    if(query(mid) >= a){
                        u = mid - 1;
                    }
                    else{
                        p = mid + 1;
                    }
                }
                if(query(p) == a){
                    fout<< p <<"\n";
                }
                else{
                    fout<<"-1\n";
                }
            }
        }
    }
    return 0;
}