# C++ Programming Code Examples

## C++ > Sorting Searching Code Examples

### Find Second Smallest of n Elements with Given Complexity Constraint

/* Find Second Smallest of n Elements with Given Complexity Constraint - Traverse the data array linearly and find the second smallest element. - The time complexity of the algorithm is O(n). - Linearly traverse the data array. - Keep track of the smallest number. - Simultaneously keep updating the second smallest number also. - Exit. */ #include<iostream> using namespace std; // A function to calculate second. int SecondSmallest(int *a, int n) { int s, ss, i; // A variable 's' keeping track of smallest number. s = a[0]; // A variable 'ss' keeping track of second smallest number. ss = a[0]; // Traverse the data array. for(i = 1; i < n; i++) { // If array element is lesser than current 's' value then update. if(s > a[i]) { ss = s; s = a[i]; } // Otherwise the number can be second smallest number so check for the condition and update 'ss'. else if(ss > a[i]) { ss = a[i]; } } // Return second smallest number. return ss; } int main() { int n, i; cout<<"Enter the number of element in dataset: "; cin>>n; int a[n]; // Take input. for(i = 0; i < n; i++) { cout<<"Enter "<<i+1<<"th element: "; cin>>a[i]; } // Print the result. cout<<"\n\nThe second Smallest number of the given data array is: "<<SecondSmallest(a, n); return 0; }

The cout is a predefined object of ostream class. It is connected with the standard output device, which is usually a display screen. The cout is used in conjunction with stream insertion operator (<<) to display the output on a console. On most program environments, the standard output by default is the screen, and the C++ stream object defined to access it is cout. The "c" in cout refers to "character" and "out" means "output". Hence cout means "character output". The cout object is used along with the insertion operator << in order to display a stream of characters.

In computer programming, loops are used to repeat a block of code. For example, when you are displaying number from 1 to 100 you may want set the value of a variable to 1 and display it 100 times, increasing its value by 1 on each loop iteration. When you know exactly how many times you want to loop through a block of code, use the for loop instead of a while loop. A for loop is a repetition control structure that allows you to efficiently write a loop that needs to execute a specific number of times.

The if...else statement executes two different codes depending upon whether the test expression is true or false. Sometimes, a choice has to be made from more than 2 possibilities. The if...else ladder allows you to check between multiple test expressions and execute different statements. In C/C++ if-else-if ladder helps user decide from among multiple options. The C/C++ if statements are executed from the top down. As soon as one of the conditions controlling the if is true, the statement associated with that if is executed, and the rest of the C else-if ladder is bypassed. If none of the conditions is true, then the final else statement will be executed.

In computer programming, we use the if statement to run a block code only when a certain condition is met. An if statement can be followed by an optional else statement, which executes when the boolean expression is false. There are three forms of if...else statements in C++: • if statement, • if...else statement, • if...else if...else statement, The if statement evaluates the condition inside the parentheses ( ). If the condition evaluates to true, the code inside the body of if is executed. If the condition evaluates to false, the code inside the body of if is skipped.

Consider a situation, when we have two persons with the same name, jhon, in the same class. Whenever we need to differentiate them definitely we would have to use some additional information along with their name, like either the area, if they live in different area or their mother's or father's name, etc. Same situation can arise in your C++ applications. For example, you might be writing some code that has a function called xyz() and there is another library available which is also having same function xyz(). Now the compiler has no way of knowing which version of xyz() function you are referring to within your code.

A relational operator is used to check the relationship between two operands. C++ Relational Operators are used to relate or compare given operands. Relational operations are like checking if two operands are equal or not equal, greater or lesser, etc. Relational Operators are also called Comparison Operators.

An array is defined as the collection of similar type of data items stored at contiguous memory locations. Arrays are the derived data type in C++ programming language which can store the primitive type of data such as int, char, double, float, etc. It also has the capability to store the collection of derived data types, such as pointers, structure, etc. The array is the simplest data structure where each data element can be randomly accessed by using its index number. C++ array is beneficial if you have to store similar elements. For example, if we want to store the marks of a student in 6 subjects, then we don't need to define different variables for the marks in the different subject. Instead of that, we can define an array which can store the marks in each subject at the contiguous memory locations.

The cin object is used to accept input from the standard input device i.e. keyboard. It is defined in the iostream header file. C++ cin statement is the instance of the class istream and is used to read input from the standard input device which is usually a keyboard. The extraction operator(>>) is used along with the object cin for reading inputs. The extraction operator extracts the data from the object cin which is entered using the keyboard. The "c" in cin refers to "character" and "in" means "input". Hence cin means "character input". The cin object is used along with the extraction operator >> in order to receive a stream of characters.

#include is a way of including a standard or user-defined file in the program and is mostly written at the beginning of any C/C++ program. This directive is read by the preprocessor and orders it to insert the content of a user-defined or system header file into the following program. These files are mainly imported from an outside source into the current program. The process of importing such files that might be system-defined or user-defined is known as File Inclusion. This type of preprocessor directive tells the compiler to include a file in the source code program.

A program shall contain a global function named main, which is the designated start of the program in hosted environment. main() function is the entry point of any C++ program. It is the point at which execution of program is started. When a C++ program is executed, the execution control goes directly to the main() function. Every C++ program have a main() function.

Program finds the Unique paritions of a given integer such that addition of a partition result an integer. A positive integer n, "generate" all possible unique ways to represent n as sum of

Full form of Ascii is American Standard Code for Information Interchange. It is a character "Encoding Scheme". Originally based on the English alphabet, every character or number

C++ Program to construct an Expression tree for an "Infix Expression". A binary expression tree is a specific application of a "binary tree" to evaluate certain expressions. These trees

A recursive function that returns true if there is an articulation point in a graph, otherwise returns false. If graph is Biconnected returns true, otherwise returns false. If this Graph is

Algorithm finds the "Chromatic Index" of the given cyclic graph. It takes the input of vertex pairs for the given number of edges. Assigns a 'color to edges' without assigning the same

Program to generate random numbers using Probability Distribution Function. Probability distribution is based on "Probability Density" function. a probability density function (pdf),