1.I Just gets(str)NOT while(!feof(stdin))scanf("%c",&choice);
2.I Clear all member in output array = ' ';
3.I print With for(i = 0;i < 80;i++)printf("%c",data[i]) NOT printf("%s",data);
4.I print output with 80 len of Symbols

NOW I GET AC!!!

Thanks a lot. Using "gets" solved my problem with WA#1. It's interesting, why has it occured?

it's very simple.
there is '\n' at the end of input line ))
gets delete it for you but you forgot about this when you read input byte after byte.