Can C++ reference member be declared without being initialized with declaration?
To many readers, this might sound the same thing, i.e. class_type *var = NULL; *var = &some_work; is same as class_type *var = &some_work; But… Read More »
Category Archives: GFacts
Facts and Question related to Style of writing programs in C/C++
Here are some questions related to Style of writing C programs: Question-1: Why i++ executes faster than i + 1 ? Answer-1: The expression i++… Read More »
Dilworth’s Theorem
Let S be a finite partially ordered set. The size of a maximal antichain equals the size of a minimal chain cover of S. This… Read More »
Storage of integer and character values in C
Integer and character variables are used so often in the programs, but how these values are actually stored in C are known to few. Below… Read More »
Vantieghems Theorem for Primality Test
Vantieghems Theorem is a necessary and sufficient condition for a number to be prime. It states that for a natural number n to be prime,… Read More »
Cauchy’s Mean Value Theorem
Suppose f(x) and g(x) are 2 functions satisfying three conditions: 1) f(x), g(x) are continuous in the closed interval a <= x <= b 2)… Read More »
Nesbitt’s Inequality
Nesbitt’s inequality is one of the simplest inequalities in mathematics. According to the statement of the inequality, for any 3 given real numbers they satisfy… Read More »
GFact 23 | (Brocard’s problem)
Brocard’s problem is to find values of m and n such that n!+1 = m2 For example, a pair (4, 5) solves the above equation.… Read More »
GFact 22 | (2^x + 1 and Prime)
A number of the form 2x + 1 (where x > 0) is prime if and only if x is a power of 2, i.e.,… Read More »
G-Fact 21 | Collatz Sequence
Starting with any positive integer N, we define the Collatz sequence corresponding to N as the numbers formed by the following operations: N → N/2… Read More »
G-Fact 20 (Cayley’s formula for Number of Labelled Trees)
Consider below questions. How many spanning trees can be there in a complete graph with n vertices? How many labelled Trees (please note trees, not… Read More »
G-Fact 19 (Logical and Bitwise Not Operators on Boolean)
Most of the languages including C, C++, Java and Python provide the boolean type that can be either set to False or True. Consider below… Read More »
G-Fact 18 | Finding nth Fibonacci Number using Golden Ratio
We have discussed different methods to find nth Fibonacci Number. Following is another mathematically correct way to find the same. nth Fibonacci Number : Here… Read More »
G-Fact 17
Storage class of a variable determines whether the item has a global or local lifetime. In C, typedef is considered as a storage class like… Read More »
fseek() vs rewind() in C
In C, fseek() should be preferred over rewind(). Note the following text C99 standard: The rewind function sets the file position indicator for the stream… Read More »