The sequence table deletes all elements with the subscript [ij]

void delete(Sqlist&L,int i,int j)
{
    int k ,delta;
    delta=j-i+1;
    for(k=j+1;k<L.length;++K)
    {
        L.data[k-delta] = L.data[k];
    }
    L.length-=delta;//改变表长
}