Is there a way to optimize this code, as this is taking hours to execute [closed]

for (i in 1:99653)
{
  for(j in 1:3226)
    {
    if (grepl(cdata$LegDigitsDialed[i],sdata$SavedPhone[j]) == TRUE)

        {
          cdata$category[i] = "Supplier"
          cdata$su_name[i] = sdata$sushortname[j]
        }

      else
        {
          cdata$category[i] = "Customer"
          cdata$su_name[i] = "Null"      
        }

    }
}

I have two data frames and I want to categorize each element of a column based on the presence in the second data frame.

My data looks like this:

>cdata
LegDigitsDialed
"a""b""c">sdata
SavedPhone
"aa""c"

What I want is;

LegDigitsDialed     category
"a""Supplier""b""Customer""c""Supplier"

So basically my pseudo code is

for (i=1,i<100000,i++)   for(j=1,j<3500,j++)
      {
        if (j contains i) //partial string matching
            populate i(different column) with some value
        else
            populate i(different column) with some other value
      }

this script in R has been running for over 24 hours now, and only one third of the records have been processed. Is there anyway to optimize this code.