Informatica Interview Question

For first round there are 40 questions and 1 hr, algorithm,sorting,data structure,5 question on SQL,3-4 on UNIX, 4-5 question based on aptitude and rest on java. For second round they select only top 10 people and starts F2F interview. In second round they asked what you have written in the resume,i know java and SQL so he start asking me OOPS concept. It was just checking our communication skills and our knowledge on what we written in the resume. For third round 8 candidates ,and i am one of them. This round was quite difficult ,he said me to write a programme to sort arrays in descending order (i have written ) and explain ,after that he said me to how to decrees time complexity, write logic for that and explain . second program on how to create dynamic linked list (which i don't know at that time). so he asked me to sorting technique and which is the best and why ? write program for that. (writes some code but i know which is wrong) After third round they announce 3-4 names which may have one technical rounds.(my name is not there sad moment)