lower

int lower(int a[],int n,int t)
{
    int m,l=0,h=n-1;
    while(l<=h)
    {
        m=(l+h)/2;
        if(a[m]==t)
        {
            h=m-1;
        }

        else if(a[m]<t)l=m+1;
        else h=m-1;
    }
    return m;
}