Code Forum

The special operator  defined  is used in ` #if ' and ` #elif ' expressions to test whether a certain name is defined as a macro.  defined  name  and  defined ( name )  are both expressions whose value is 1 if  name  is defined as a macro at the current point in the program, and 0 otherwise. Thus,  #if defined MACRO  is precisely equivalent to  #ifdef MACRO . defined  is useful when you wish to test more than one macro for existence at once. For example, #if defined (__vax__) || defined (__ns16000__) would succeed if either of the names  __vax__  or  __ns16000__  is defined as a macro. Conditionals written like this: #if defined BUFSIZE && BUFSIZE >= 1024 can generally be simplified to just  #if BUFSIZE >= 1024 , since if  BUFSIZE  is not defined, it will be interpreted as having the value zero. If the  defined  operator appears as...

given an array of elements (all elements are unique ) , given a sum s find all the subsets having sum s. for ex array {5,9,1,3,4,2,6,7,11,10} sum is 10 possible subsets are {10}, {6,4}, {7,3}, {5,3,2}, {6,3,1} etc. there can be many more. also find the total number of these subsets.

Introduction To understand the concept of endianness ,you need to be familiar, at a highly abstract level, with memory. All you need to know about memory is that it's one large array. The array contains bytes. In the computer world, people use address to refer to the array locations. Endianness The attribute of a system that indicates whether integers are represented with the most significant byte stored at the lowest address (big endian) or at the highest address (little endian). Each address stores one element of the memory array. Each element is typically one byte. In some memory configurations, each address stores something besides a byte. However, those are extremely rare so, for now, let's make the broad assumption that all memory addresses store bytes. Storing bytes in memory I refer to 32 bits, which is the same as four bytes. Integers or single-precision floating point numbers are all 32-bits long. But since each memory address can store a single byte and not fo...

I came across this concept while facing one of my interview then thought to share the concept with you all.It may not seem to be big thing for many of us but sometime prove to be handy while declaring variable arrays in  structure. Any query related to this is highly appreciated. Flexible array members allow incomplete array struct members without bounds . Consider : #include struct flex {     int mem ; // Flex array must have a named member     int arrayWoBoundsSpecified []; // Flex member must be last member }; struct NotAflex {     int a []; // Error: Flex member must be last member                     // Therefore incomplete type should be complete     int mem ; }; int main () {      size_t len = sizeof ( struct flex );     // Flexible array members might be useful for getting variable length information.   ...