Dassault Systèmes Interview Question

3 Programs-->1.Remove duplicate charcaters from string. 2.implement a vending machine. 3.to find weather string consists of equal no of repeated characters.e.g aabbcc-->this is even string becoz all characters count is same and program must return true. aabbc-->this is odd string becoz all characters count is not same(c appears only once ) and program must return false. 1 last question after every technical will be of logical type(I don't remeber the que) .Search for such questions and prepare,it will be asked surely.