Cod sursa(job #3265366)

Utilizator TeodorG8Cirstov Teodor TeodorG8 Data 29 decembrie 2024 18:46:45
Problema Arbori indexati binar Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.09 kb
#include <fstream>

using namespace std;

ifstream cin("aib.in");
ofstream cout("aib.out");

int n,m,a,b,c,aib[100005];
void update(int p, int k)
{
    for(int i=p; i<=n; i+=(i&-i))
        aib[i]+=k;
}

int query(int p)
{
    long long sum=0;
    for(int i=p; i>=1; i-=(i&-i))
        sum+=aib[i];
    return sum;
}
int cb(int sk)
{
    int st=1,dr=n;
    while(st<=dr)
    {
        int mid=(st+dr)/2;
        int smid=query(mid);
        if(smid==sk)
            return mid;
        else if(smid<sk)
            st=mid+1;
        else
            dr=mid-1;
    }
    return -1;
}
int main()
{
    cin>>n>>m;
    for(int i=1; i<=n; i++)
        {
            cin>>a;
            update(i,a);
        }
    for(int ceva=1; ceva<=m; ceva++)
    {
        cin>>c;
        if(c==0)
        {
            cin>>a>>b;
            update(a,b);
        }
        else if(c==1)
        {
            cin>>a>>b;
            cout<<query(b)-query(a-1)<<"\n";
        }
        else
        {
            cin>>a;
            cout<<cb(a)<<"\n";
        }
    }
}