₦airaland Forum

Implement using iteration recursion a substring generator that generates all the substrings of a string. For example, the substrings of the string "rum" are the seven strings

"r", "ru", "rum", "u", "um", "m", ""

Goodluck

Correction sir

What correction?

$myString = 'rum';
$myString2 = strrev($myString);

$myStrLen = strlen($myString);

for ($x = 0; $x < $myStrLen; $x++){

     echo substr($myString, $x). "\t\t";
     echo substr($myString2, $x). "\t\t";
     }

Can this be usefull

Nope incorrect

with python

code:

def nairaland(word):
    #w = []-----------> redundant. I forgot to delete
    for x in range(len(word)):
        t = x
        for j in range(1,len(word[x:])+1):
            print word[t:t+j]
    print '""'

If you must have a recursion:

def nairaland_r(word, flag=1, w=None):
    #if not w: ---->redundant
     #   l = []
    #else:
     #   l = w
        
    if flag > len(word):
        print '""'
    else:
        for x in range(len(word)):
            print word[x:x+flag]
            if x+1 > len(word)-flag:
                break
        f = flag + 1

        nairaland_r(word,f,l)

Edit:

def nairaland(word):
    for x in range(len(word)):
        t = x
        for j in range(1,len(word[x:])+1):
            print word[t:t+j]
    print '""'

def nairaland_r(word, flag=1):
    if flag > len(word):
        print '""'
    else:
        for x in range(len(word)):
            print word[x:x+flag]
            if x+1 > len(word)-flag:
                break
        f = flag + 1

        nairaland_r(word,f)

Errrm unfortunaely i realy dont know python so what was ur result with the word 'rum' and 'fayimora'

sorry, nairaland-bot refused to inform me that you had replied

no-recursion:
rum---------------> r ru rum u um m ""
fayimora---------> f fa fay fayi fayim fayimo fayimor fayimora a ay ayi ayim ayimo ayimor ayimora y yi yim yimo yimor yimora i im imo imor imora m mo mor mora o or ora r ra a ""

iterative recursion:
rum---------------> r u m ru um rum ""
fatimora---------> f a y i m o r a fa ay yi im mo or ra fay ayi yim imo mor ora fayi ayim yimo imor mora fayim ayimo yimor imora fayimo ayimor yimora fayimor ayimora fayimora ""

P.S i've edited my post to take care of some redundancies

Cool

So just 1 person was able to solve this, wow!

.

I almost made a mock of myself rushing to post something I'd done in notepad on a PC without dev tools. Thank God I noticed the errors immediately I posted, otherwise man for no fit talk for programming section again!

Here goes (in C#):

    void GetAllSubstrings(string input, int startIndex)
    {
        int innerStartIndex = startIndex;
        string substring = input[innerStartIndex].ToString();
        Console.WriteLine(substring);
        while (innerStartIndex < input.Length)
        {
            innerStartIndex++;
            if (innerStartIndex == input.Length)
                break;
            substring += input[innerStartIndex];
            Console.WriteLine(substring);
        }
        startIndex++;
        if (startIndex < input.Length)
            GetAllSubstrings(input, startIndex);
    }

[color=#00BB00]public[/color] [color=#00BB00]class[/color] arr {
[color=#00BB00]public[/color] [color=#00BB00]void[/color] mm(){
       String s = [color=#FF0000]"[/color][color=#FF0000]m[/color][color=#FF0000]o[/color][color=#FF0000]b[/color][color=#FF0000]i[/color][color=#FF0000]n[/color][color=#FF0000]g[/color][color=#FF0000]a[/color][color=#FF0000]"[/color];
       StringBuilder ss = [color=#FF9D00]new[/color] StringBuilder(s);
       String sss = ss.reverse().toString();
     [color=#0000EE]//   System.out.println(ss.reverse());
[/color]       rec(sss,s); }
  [color=#00BB00]public[/color] [color=#00BB00]void[/color] rec(String sss,String s ){
   [color=#FF9D00]for[/color]([color=#00BB00]int[/color] e = sss.length(); e>=[color=#FF0000]0[/color]; e--){
     StringBuilder lll = [color=#FF9D00]new[/color] StringBuilder(sss.substring(e));
     String ssss = lll.reverse().toString();
System.out.println(ssss);
}
       [color=#FF9D00]for[/color]([color=#00BB00]int[/color] z = [color=#FF0000]1[/color]; z<=s.length(); z++){
     StringBuilder lll = [color=#FF9D00]new[/color] StringBuilder(sss.substring(z));
     String ssss = lll.reverse().toString();
System.out.println(s.substring(z)); } }
[color=#00BB00]public[/color] [color=#00BB00]static[/color] [color=#00BB00]void[/color] main(String [] args){
arr psvm = [color=#FF9D00]new[/color] arr();
    psvm.mm();}}


Output ::

m
mo
mob
mobi
mobin
mobing
mobinga
obinga
binga
inga
nga
ga
a





-----------------
Non recursive -- //Would do that later.
-----------------

Why break your head on recursion when what you need is a substring generator?

In Ruby . . .

def substring_generator str
    1.upto(str.split('').size).each do |n|
        pp str.split('').combination(n).to_a
    end
end


Less clutter, more readable, gets the job done!

Thats why its a challenge! Its not an assignment so yeah Recursion

Fayimora:
Thats why its a challenge! Its not an assignment so yeah Recursion

this is the more reason to assume that this is some assignment and you're looking for the best solution. My opinion though -- it may not necessarily be right

Again its a challenge! AM not looking for the best solution but challenging you to recursion.

Fayimora:
Again its a challenge! AM not looking for the best solution but challenging you to recursion.

So far, my solution is the only recursive one that produces the expected result, you can test it.
Bros, abeg gif me di trophy na! Lol!

Ok tell me How to run it. I know nothing about c#

Fayimora:
Ok tell me How to run it. I know nothing about c#

How about C++?
This is the same code in a simple C++ class:

#include <iostream>
#include <string>
using namespace std;

class SubstringGen
{
public:
	void GetAllSubstrings(string input, int startIndex)
	{
		int innerStartIndex = startIndex;
		string substring(1, input[innerStartIndex]);
		cout << substring << endl;
		while (innerStartIndex < input.length())
		{
			innerStartIndex++;
			if (innerStartIndex == input.length())
				break;
			substring += input[innerStartIndex];
			cout << substring << endl;
		}
		startIndex++;
		if (startIndex < input.length())
			GetAllSubstrings(input, startIndex);
	};
};

You can call it like so:

SubstringGen substringGen;
substringGen.GetAllSubstrings("fayimora", 0);