C++ for loop because i can't figure it out

Question

Hello i want to add for loop that will print my code for 20 times or 50 times .. but i really can't figure it out since i already add for function but it still give only 1 result :D

 #include <bits/stdc++.h> 
using namespace std; 

const int MAX = 36; 

// 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', '0', '1', '2',
                        '3', '4', '5', '6', '7', '8', '9'}; 

    string res = ""; 
    for (int i = 0; i < n; i++) 
        res = res + alphabet[rand() % MAX]; 
    
    return res; 
} 

// Driver code 
int main() 
{ 
srand(time(NULL)); 
int n = 20; 
cout << printRandomString(n); 
return 0; 
}

What do you mean? Doesn't your code print a string of 20 random characters? — Yksisarvinen, Jul 15 '20 at 09:49
yes it does , but i want it to make a loop for example :g87asdasd876asd 876asdyas87djhasd — ẬħmȜđ Wāly, Jul 15 '20 at 09:51
If you want to generate random alphabets 20 times it is working completely fine. What else do you want please elaborate? — Ayush Jain, Jul 15 '20 at 09:52
then add another loop outside that, which does your existing loop multiple times... — underscore_d, Jul 15 '20 at 09:53
@AyushJain i need my code to give me many results not only 1 result , i used for function but still don't figure why it doesn't work xD — ẬħmȜđ Wāly, Jul 15 '20 at 09:53

score 2 · Accepted Answer · answered Jul 15 '20 at 09:53

Just run your function in a loop

int main() 
{ 
    srand(time(NULL)); 
    int n = 20; 
    for (int i = 0; i < 50; ++i)
        cout << printRandomString(n); 
    return 0; 
}

Side note: #include <bits/stdc++.h> is bad, using namespace std; is bad and they are especially bad hen combined together.

cse · Answer 2 · 2020-07-15T16:00:52.077

You need to set a loop in main accordingly:

int len = 20 + ( rand() % ( 50 - 20 + 1 ) );
for(int i = 0; i< len; i++)
{
    int n = 20 + ( rand() % ( 50 - 20 + 1 ) );
    cout << printRandomString(n)<<endl;
}

Following is complete working code. See it working here:

#include <iostream>
using namespace std; 

const int MAX = 36;
const int PRINT_MIN = 20;
const int PRINT_MAX = 50;


// 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', '0', '1', '2',
                        '3', '4', '5', '6', '7', '8', '9'}; 

    string res = "";
    for (int i = 0; i < n; i++) 
        res = res + alphabet[rand() % MAX]; 
    
    return res; 
} 

// Driver code 
int main() 
{ 
    srand(time(NULL)); 
    int len = PRINT_MIN + ( rand() % ( PRINT_MAX - PRINT_MIN + 1 ) );
    for(int i = 0; i< len; i++)
    {
        int n = PRINT_MIN + ( rand() % ( PRINT_MAX - PRINT_MIN + 1 ) );
        cout << printRandomString(n)<<endl;
    } 
    return 0; 
}

Thanks dude it's useful too – ẬħmȜđ Wāly Jul 15 '20 at 10:00 — ẬħmȜđ Wāly, Jul 15 '20 at 10:00

score 1 · Answer 3 · answered Jul 15 '20 at 09:57

Your Code as it is will only result in 1 string of 20 characters. if you want to print this string say m number of times, then you should change your main() function to the following:

int main() 
{ 

srand(time(NULL)); 
int n = 20,m=30; 
for(int i=0;i<m;i++)
{
   cout << printRandomString(n); 
}
return 0; 
}

score 0 · Answer 4 · answered Jul 15 '20 at 10:16

I think this is what you want to implement.

#include <iostream> 
using namespace std; 
const int MAX = 36; 
char printRandomString() 
{ 
    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', '0', '1', '2',
                        '3', '4', '5', '6', '7', '8', '9'}; 
   return alphabet[rand() % MAX]; 
} 

// Driver code 
int main() 
{ 
int n;
scanf("%d",&n);
for(int i;i<n;i++){
printf("%c",printRandomString()); 
}
return 0; 
}

and as @Yksisarvinen mentioned ,try not to use #include <bits/stdc++.h> .

C++ for loop because i can't figure it out

4 Answers4