Cod sursa(job #2040873)

Utilizator Liviu_Ionut_MoantaMoanta Ionut Liviu Liviu_Ionut_Moanta Data 16 octombrie 2017 17:18:19
Problema Arbori indexati binar Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.05 kb
#include<fstream>
using namespace std;
ifstream fin("aib.in");
ofstream fout("aib.out");
int n,m,i,x,a,b,c,val,st,dr,mid;
int A[100005];
int query(int p){
    int r=0;
    for(;p;p-=(p&(-p))){
        r+=A[p];
    }
    return r;
}
void update(int p,int x){
    for(;p<=n;p+=(p&(-p))){
        A[p]+=x;
    }

}
int main(){
    fin>>n>>m;
    for(i=1;i<=n;i++){
        fin>>x;
        update(i,x);
    }
    for(i=1;i<=m;i++){
        fin>>val>>a;
        if(val==0){
            fin>>b;
            update(a,b);
            continue;
        }
        if(val==1){
            fin>>b;
            fout<<query(b)-query(a-1)<<"\n";
            continue;
        }
        st=1;
        dr=n;
        while(st<=dr){
            mid=(st+dr)/2;
            if(query(mid)>=a){
                dr=mid-1;
            }
            else{
                st=mid+1;
            }
        }
        if(query(st)==a){
            fout<<st<<"\n";
        }
        else{
            fout<<"-1"<<"\n";
        }
    }
    return 0;
}