You won't need an array. The simplest method to turn an integer into a grade from your table is to use a series of cmp
and jg
instructions. For example:
cmp score, 90
jg Grade_A
cmp score, 80
jg Grade_B
cmp score, 70
jg Grade_C
cmp score, 60
jg Grade_D
- - and so on - -
I know you went to arrays for efficiency's sake, but try not to overthink these things. Keep it simple.
You'll need some way of converting the string you're getting from stdin into an integer (IIRC)