C++ randdom Alphabet using ascii characters 65-91 generator

Question

0.00/5 (No votes)

See more:

Using rand function to generate, Construct an array of upper case letters of size (at least 20) not more than 30.

This is what my program is.. to generate an element between the range from 65 to 91 and cast it, can get any letter from A to Z... After the generation, using only one loop, try to move all the letters smaller than letter 'M' to the left hand side of the array and all the letters greater than 'M' to the right side of the array..

the output should be:

Given the follwing array:
A D F Y H J I O L B G E M Y R W A Q (Random)

iterative swap of array
??????

Given the follwing array:
A D F Y H J I O L B G E M Y R W A Q (Random)

Recursive swap of array
????????

help me with my code below

#include <iostream>
#include <iomanip>
#include <cstdlib>
#include <ctime>

using namespace std;

void characters(char[]);
void printChar(char[]);
void swapChar(char[]);

int main ()
{
	char c[26];
	
	characters(c);
	cout << "Given the following array" << endl;
	printChar(c);
	swapChar(c);
	cout << "Iterative swap of array" << endl;
	printChar(c);

}

void characters(char c[])
{
	int seed;
	
	int sum = rand();
	srand(time(NULL));
	
	for(int i = 65; i <= 90; i++)
	{
		c[sum] = i;	   	   	   
		sum++;
	}

}

void printChar(char c[])
{
	for(int i = 0; i <= 25; i++)
	{
		
		cout << c[i] << " ";
	}	 
		cout << endl;
}

void swapChar(char c[])
{
	int temp;
	for(int i = 0; i <= 25; i++)
	{
		if(c[i] > c[12])
		{
			temp = c[i];
			c[i] = c[26-i-1];
			c[26-i-1] = temp;
		}
		
	}
}

Posted 16-Aug-10 6:13am

Mzbarz1986

Add a Solution

4 solutions

Solution 1

I think error is in characters(char []) function.

Try this:

void characters(char c[])
{
	bool used[25];

	memset(used, 0, 25 * sizeof(bool));
	srand(time(NULL));
	
	for(int i = 65; i <= 90; i++)
	{		
		int index;

		do {
			index = rand() % 25;
		} while (used[index]);

		used[index] = true;
		c[index] = i;
	}

}

Posted 16-Aug-10 6:25am

Nyarost

Comments

Mzbarz1986 16-Aug-10 12:28pm

Will the whole program work???

Nyarost 16-Aug-10 12:30pm

Well, didn't check all code. But you'll at least get correct randomized array. Your version heads to access violation. You can give it a try.

Mzbarz1986 16-Aug-10 12:31pm

Did tried it out... but no output.... blank.. waiting.. somthing is wrong.. somewhere

Solution 2

without swapChar() it should look like this

#include <iostream>
#include <iomanip>
#include <cstdlib>
#include <ctime>
#include <cstring>

using namespace std;

void characters(char[]);
void printChar(char[]);
void swapChar(char[]);

int main ()
{
	char c[26];
	
	characters(c);
	cout << "Given the following array" << endl;
	printChar(c);
	swapChar(c);
	cout << "Iterative swap of array" << endl;
	printChar(c);
	return 0;
}

void characters(char c[])
{
	bool used[26];

	memset(used, 0, 26 * sizeof(bool));
	srand(time(NULL));
	
	for(int i = 65; i <= 90; i++)
	{		
		int index;

		do {
			index = rand() % 26;
		} while (used[index]);

		used[index] = true;
		c[index] = i;
	}

}

void printChar(char c[])
{
	for(int i = 0; i <= 25; i++)
	{
		
		cout << c[i] << " ";
	}	 
	cout << endl;
}

The only thing left is this function. Homework? :)

Posted 16-Aug-10 6:38am

Nyarost

Updated 16-Aug-10 6:40am

v3

Comments

Mzbarz1986 16-Aug-10 12:42pm

How to do the swapChar function to swap the first set of characters to iterative swap????

Nah.. trying out a program my friend sent me...

Nyarost 16-Aug-10 12:50pm

Remember, you have to also think by yourself ;)

Mzbarz1986 16-Aug-10 12:52pm

trying too.. lol... i'm not as great as my friend was.. he gave me some pointers.. but still dont understand the swap.. i've got learned bit of the swap using 26-i-1

Mzbarz1986 16-Aug-10 12:55pm

I just need to complete this by tomorrow morning to show him.. this is how far as i can do

Solution 3

Some kind of this, I think:

void swapChar(char c[])
{
	int temp;
	int l_index = 0;	

	for(int i = 0; i <= 25; i++)
	{
		if (c[i] < 'M') {
			temp = c[i];
			c[i] = c[l_index];
			c[l_index++] = temp;
		}
	}
}

Posted 16-Aug-10 9:48am

Nyarost

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Aescleal · Accepted Answer · 2010-08-16T11:45:00

Rather than messing about with hand rolled loops why not try the magic of the standard C++ library?

-std::random_shuffle can give you a random vector of capital letters:

const char letters[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
std::vector<char> stirred( letters, letters + 26 );
std::random_shuffle( stirred.begin(), stirred.end() );</char>

- std::partition can give you greater than 'M' stuff:

bool less_than_M( char c )
{
    return c < 'M';
}

std::partition( stirred.begin(), stirred.end(), less_than_M );

You really don't want to fiddle about with low level stuff like pointers and arrays when there are better ways of representing your data and doing the operations you want.

Cheers,

Ash

Edited as I got the sign in less_than_M the wrong way 'round, complete spanner that I am...

C++ randdom Alphabet using ascii characters 65-91 generator

4 solutions

Solution 1

Solution 2

Solution 3

Solution 5

Add your solution here

Preview 0

Existing Members

...or Join us