Consider the program:

#include <iostream>
using namespace std;

#include <stdlib.h>
#include <time.h>

int main()
{	
	char alphabets[26] = {'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'};
	char rString[20];

	srand(time(NULL));

	int i=0;
	while(i<20) {
		int temp = rand() % 26;
		rString[i] = alphabets[temp];
		i++;
	}

	for(i=0; i<20; i++)
		cout<<rString[i];

	return 0;
}

Output

qaicgosutvmscsfufpfk

In this program first we take two character arrays, one to store all the alphabets and other to print random characters into it. To keep it simple we have taken the length as 20.

Now we initialize the seed to current system time so that every time a new random seed is generated.

Next, in the while loop, we loop through the length of the random string (20 here) and store random generated alphabets. We take a temp variable to generate a number between 0-26. Then we provide this number to alphabets array and a random string is generated.

After that we print the final random generated string.