In this article, we will discuss how to generate a random password of a given length consists of any characters.
Approach:
- The below-given program involves basic concepts like variables, data types, array, loop, etc.
- Follow the below steps to solve this problem:
- Take the length of the password and declare a character array of that length to store that password.
- Declare character array of all the capital letters, small letters, numbers, special characters.
- Now according to the program below, respective if-else gets executed and a random password gets generated.
Below is the program of the above approach:
C
// C program for the above approach #include <math.h> #include <stdio.h> #include <stdlib.h> #include <time.h> // Function to randomly generates password // of length N void randomPasswordGeneration( int N)
{ // Initialize counter
int i = 0;
int randomizer = 0;
// Seed the random-number generator
// with current time so that the
// numbers will be different every time
srand ((unsigned int )( time (NULL)));
// Array of numbers
char numbers[] = "0123456789" ;
// Array of small alphabets
char letter[] = "abcdefghijklmnoqprstuvwyzx" ;
// Array of capital alphabets
char LETTER[] = "ABCDEFGHIJKLMNOQPRSTUYWVZX" ;
// Array of all the special symbols
char symbols[] = "!@#$^&*?" ;
// Stores the random password
char password[N];
// To select the randomizer
// inside the loop
randomizer = rand () % 4;
// Iterate over the range [0, N]
for (i = 0; i < N; i++) {
if (randomizer == 1) {
password[i] = numbers[ rand () % 10];
randomizer = rand () % 4;
printf ( "%c" , password[i]);
}
else if (randomizer == 2) {
password[i] = symbols[ rand () % 8];
randomizer = rand () % 4;
printf ( "%c" , password[i]);
}
else if (randomizer == 3) {
password[i] = LETTER[ rand () % 26];
randomizer = rand () % 4;
printf ( "%c" , password[i]);
}
else {
password[i] = letter[ rand () % 26];
randomizer = rand () % 4;
printf ( "%c" , password[i]);
}
}
} // Driver Code int main()
{ // Length of the password to
// be generated
int N = 10;
// Function Call
randomPasswordGeneration(N);
return 0;
} |
Output:
51WAZMT?Z$
Time Complexity: O(N)
Auxiliary Space: O(26)
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