Cod sursa(job #2104215)

Utilizator DavidLDavid Lauran DavidL Data 11 ianuarie 2018 13:48:28
Problema Datorii Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.31 kb
#include <fstream>
#define MAX 16000
using namespace std;
ifstream fi("datorii.in");
ofstream fo("datorii.out");

int A[5*MAX];
int pos,val;
int st,dr;
int suma;
int n,m;

void update(int nod,int l,int r)
{
    /// numarul de pe pos e marit cu val

    if (l==r)
    {
        A[nod]+=val;
        return;
    }
    /// mergem la copii
    int mij=(l+r)/2; /// [l,mij] sau [mij+1,r]
    if (pos<=mij)
        update(2*nod,l,mij);
    else
        update(2*nod+1,mij+1,r);

    A[nod]=A[2*nod]+A[2*nod+1];

}

void query(int nod,int l,int r)
{
    /// intervalul se afla in [st,dr]
    if (st<=l && r<=dr)
    {
        suma+=A[nod];
        return;
    }
    int mij=(l+r)/2; /// [l,mij] sau [mij+1,r]
    if (st<=mij)
        query(2*nod,l,mij);
    if (mij<dr)
        query(2*nod+1,mij+1,r);

}

int main()
{
    fi>>n>>m;
    for (int i=1; i<=n; i++)
    {
        int x;
        fi>>x;
        pos=i,val=x;
        update(1,1,n);
    }
    for (int i=1; i<=m; i++)
    {
        int c,a,b;
        fi>>c>>a>>b;
        if (c==0)
        {
            pos=a,val=-b;
            update(1,1,n);
        }
        else
        {
            suma=0;
            st=a,dr=b;

            query(1,1,n);
            fo<<suma<<"\n";
        }
    }
    return 0;
}