SID interview questions

guys i want share my technical interview experience in robosoft technologies. they ask me to chose one any language which i have compatible.so i choose c programming language.. first they told me to write c program to convert floating point number to hex decimal number.i wrote program..then they asked to me to trace the code. -->then asked wrp copy one string to another string without using standard function. -->then asked me to wrp to find largest possible number from given number.ex input 38946 output 98643. -->then asked some question on pointer,dangling pointer,write code for dangling pointer. -->dangling pointer scenario code. -->then asked me to how u avoid dangling pointer situation. -->then asked me to definition of stack,queue,tree,linked list,dynamic memory allocation ,static memory allocation -->write code for dynmic memory allocation . -->asked me to write program to find the given linked list is circular linked list or not --> so overall the mainly look at ur programming skill,asked me almost question from data structure if ur chosen c language.they nearly took 90 minutes .finally i am shortlisted for hr round...in hr round asked me about our family,about robosoft company etc.