I got this error:
exit status 1 stray '#' in program
How can I remove this error..?
int keys = {1,2,3,A,4,5,6,B,7,8,9,C,*,0,#,D};
There are several -more or less severe- issues in your one line of code
const char keys[] = {'1','2','3','A'
,'4','5','6','B'
,'7','8','9','C'
,'*','0','#','D' };
( Find the differences :) )
Depending on your usage, you eventually even need a 2-dimensional array
const char keys[4][4] = ...
{'1', ...'#', 'D'}
keys
are integers ... you need to rethink what you are doing#
doing there, there's no way to answer your question.