 # C++ Programming Code Examples

## C++ > Sorting Searching Code Examples

### C++ Program to Implement Radix Sort

/* C++ Program to Implement Radix Sort This is a C++ Program to Sort the Given Data using Radix sort. - In this algorithm sorting of data is done from least significant digit to most significant digit. - Here we need 10 different spaces labeled 0 to 9. - Assume we have 'n' number of inputs. - Let 'd' be the maximum number of digit the input data has. - The time complexity for radix sort is O(n*d). - Radix sort solves the problem of card sorting by sorting on the least significant digit first. - Get the maximum value from the input array which has 'd' digits. - Starting from least significant digit, sort the data. - Take this data as input for next significant digit. - Run the iteration till d digit. - Display the result. - Exit. */ #include <iostream> using namespace std; // Get maximum value from array. int getMax(int arr[], int n) { int max = arr; for (int i = 1; i < n; i++) if (arr[i] > max) max = arr[i]; return max; } // Count sort of arr[]. void countSort(int arr[], int n, int exp) { // Count[i] array will be counting the number of array values having that 'i' digit at their (exp)th place. int output[n], i, count = {0}; // Count the number of times each digit occurred at (exp)th place in every input. for (i = 0; i < n; i++) count[(arr[i] / exp) % 10]++; // Calculating their cumulative count. for (i = 1; i < 10; i++) count[i] += count[i-1]; // Inserting values according to the digit '(arr[i] / exp) % 10' fetched into count[(arr[i] / exp) % 10]. for (i = n - 1; i >= 0; i--) { output[count[(arr[i] / exp) % 10] - 1] = arr[i]; count[(arr[i] / exp) % 10]--; } // Assigning the result to the arr pointer of main(). for (i = 0; i < n; i++) arr[i] = output[i]; } // Sort arr[] of size n using Radix Sort. void radixsort(int arr[], int n) { int exp, m; m = getMax(arr, n); // Calling countSort() for digit at (exp)th place in every input. for (exp = 1; m/exp > 0; exp *= 10) countSort(arr, n, exp); } int main() { int n, i; cout<<"\nEnter the number of data element to be sorted: "; cin>>n; int arr[n]; for(i = 0; i < n; i++) { cout<<"Enter element "<<i+1<<": "; cin>>arr[i]; } radixsort(arr, n); // Printing the sorted data. cout<<"\nSorted Data "; for (i = 0; i < n; i++) cout<<"->"<<arr[i]; return 0; }

As the name already suggests, these operators help in assigning values to variables. These operators help us in allocating a particular value to the operands. The main simple assignment operator is '='. We have to be sure that both the left and right sides of the operator must have the same data type. We have different levels of operators. Assignment operators are used to assign the value, variable and function to another variable. Assignment operators in C are some of the C Programming Operator, which are useful to assign the values to the declared variables. Let's discuss the various types of the assignment operators such as =, +=, -=, /=, *= and %=. The following table lists the assignment operators supported by the C language:

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.

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 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.

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 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.

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.

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.

#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.

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.

The pointer in C++ language is a variable, it is also known as locator or indicator that points to an address of a value. In C++, a pointer refers to a variable that holds the address of another variable. Like regular variables, pointers have a data type. For example, a pointer of type integer can hold the address of a variable of type integer. A pointer of character type can hold the address of a variable of character type. You should see a pointer as a symbolic representation of a memory address. With pointers, programs can simulate call-by-reference. They can also create and manipulate dynamic data structures. In C++, a pointer variable refers to a variable pointing to a specific address in a memory pointed by another variable.

'Sum of digits' means add all the digits of any number, we take any number like 358. Its sum of all digit is '3+5+8=16'. Using given code we can easily write c++ program. Enters any num

An object can be passed to a function just like we pass structure to a function. Here in class A we have a "function disp()" in which we are passing the object of class A. Similarly we can

This is a C++ program "Displays the Nodes" which are strongly connected to each other. Strongly connected subgraphs are those in which a path is available from any node of