Ye i have this riddle and if you can solve it without looking it up online, tho i doubt it is?

Simple: Each prisoner who visits the central living room writes his or her name on the wall...if a particular prisoner visits two or more times s/he writes her/his name followed by 2nd visit, 3rd visit etc. If there is a case of prisoners having same names then they would use another name. After writing their name each prisoner adds up the names (Not counting the repeat visits). When the 100 prisoner visits he/she can safely make the statement that all the prisoners have visited and get theselves free!!!.