Prerequisite : rand() and srand()
Given all alphabets in a character array, print a string of random characters of given size.
We will use rand() function to print random characters. It returns random integer values. This number is generated by an algorithm that returns a sequence of apparently non-related numbers each time it is called.
- A ubiquitous use of unpredictable random characters is in cryptography, which underlies most of the schemes which attempt to provide security in modern communications (e.g. confidentiality, authentication, electronic commerce, etc).
- Random numbers are also used in situations where “fairness” is approximated by randomization, such as selecting jurors and military draft lotteries.
- Random numbers have uses in physics such as electronic noise studies, engineering, and operations research. Many methods of statistical analysis, such as the bootstrap method, require random numbers.
Pseudo code :
1. First we initialize two character arrays, one containing all the alphabets and other of given size n to store result.
2. Then we initialize the seed to current system time so that every time a new random seed is generated.
3. Next, we use for loop till n and store random generated alphabets.
Below is C++ implementation of above approach :
C++
// CPP Program to generate random alphabets#include <bits/stdc++.h>using namespace std; const int MAX = 26; // Returns a string of random alphabets of// length n.string printRandomString(int n){ char alphabet[MAX] = { 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z' }; string res = ""; for (int i = 0; i < n; i++) res = res + alphabet[rand() % MAX]; return res;} // Driver codeint main(){ srand(time(NULL)); int n = 10; cout << printRandomString(n); return 0;} |
Java
// JAVA Program to generate random alphabetsimport java.util.*; class GFG{ static int MAX = 26; // Returns a String of random alphabets of// length n.static String printRandomString(int n){ char []alphabet = { 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z' }; String res = ""; for (int i = 0; i < n; i++) res = res + alphabet[(int) (Math.random() * 10 % MAX)]; return res;} // Driver codepublic static void main(String[] args){ int n = 10; System.out.print(printRandomString(n));}} // This code is contributed by Rajput-Ji |
C#
// C# Program to generate random alphabetsusing System; class GFG{static int MAX = 26; // Returns a String of random alphabets of// length n.static String printRandomString(int n){ char []alphabet = { 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z' }; Random random = new Random(); String res = ""; for (int i = 0; i < n; i++) res = res + alphabet[(int)(random.Next(0, MAX))]; return res;} // Driver codepublic static void Main(){ int n = 10; Console.Write(printRandomString(n));}} |
Output :
jgyuihhlxb
This program will print different characters every time we run the code.
