Question

Combinations of Recursion

there is a vector<vector<string> > v =

v[0] = { Blue}

v[1] = { Pig, Dog }

v[2] = { jump }

v[3] = { low, high}

________________________________

the cout result will be like (a sentence must have v[1] and v[2], but v[0] and v[3] is not required in the sentence)

Pig jump

Pig jump low

Pig jump high

Dog jump

Dog jump low

Dog jump high

Blue Pig jump

Blue Pig jump low

Blue Pig jump high

Blue Dog jump

Blue Dog jump low

Blue Dog jump high

__________________________

Please use this function to do the recursion:

void recur_sentence(vector<vector<string> >& elements, int position)

{

}

***position means where you are. (at v[0], v[1], v[2] or v[3])

**************Please do this in recursion!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Answer 1

I have implemented the recursive function as requested in the question

Below is the C++ code and i have commented the codes to explain its functionality

*******************************C++ CODE***********************************

#include <stdio.h>
#include <iostream>
#include <algorithm>   
#include <vector>
using namespace std;

//Global variable declared
vector<string> fullList;
int loopCount = 1;

//Recursive function to build the string combinations
void recur_sentence(vector<vector<string>> &elements, int position, string strSoFar)
{
//If the position is 2 that means two words formed
if (position == 2)
{
//Check the word combination already added in word list
bool notFound = true;
for (int i=0; i<fullList.size(); i++)
{
if(fullList[i] == strSoFar)
{
notFound = false;
}
}
//If word combination not exist then add to list
if(notFound)
fullList.push_back(strSoFar);
}
//If the position is 3 that means three words formed
if (position == 3)
{
//Check the word combination already added in word list
bool notFound = true;
for (int i=0; i<fullList.size(); i++)
{
if(fullList[i] == strSoFar)
{
notFound = false;
}
}
//If word combination not exist then add to list
if(notFound)
fullList.push_back(strSoFar);
}
//If the position is 4 that means four words formed
if (position >= elements.size())
{
//Check the word combination already added in word list
bool notFound = true;
for (int i=0; i<fullList.size(); i++)
{
if(fullList[i] == strSoFar)
{
notFound = false;
}
}
//If word combination not exist then add to list
if(notFound)
fullList.push_back(strSoFar);
  
//If four word combination formed then call the recursive function
if(loopCount >= 4 && elements.size() == 4)
{
//Remove one element from list
elements.erase(elements.begin());
recur_sentence(elements, 0, "");
}
loopCount = loopCount + 1;
return;
}
//Form loop of the elements vector
for (int i=0; i<elements[position].size(); i++)
{
recur_sentence(elements, position+1, strSoFar+ " " + elements[position][i]);
}
};

int main()
{
//Vector declared
vector<vector<string>> v(4);
v[0] = { "Blue" };
v[1] = { "Pig", "Dog" };
v[2] = { "jump" };
v[3] = { "low", "high" };
  
//Recursive function called
recur_sentence(v, 0, "");
  
//Print the data of string formed from recursive function
for (int i=0; i<fullList.size(); i++)
{
cout<<fullList[i]<<endl;;
}
  
return 0;
}

********************************END*********************************

#include <stdio.h> #include <iostream» #include <algorithm» #include <vector» using namespace std; //GLobal variable declared vector string fullist; int loopCount 1; //Recursive function to build the string combinations void recur_sentence (vector<vector<string>> &elements, int position, string strSoFar) //If the position is 2 that means two words formed if (position2) //Check the word combination already added in word list bool notFoundtrue; for (int i-0; iful!List . size(); i++) if(fulllist[i]strSoFar) notFound false; //If word combination not exist then add to list if(notFound) fulllist.push_back(strSoFar); //If the position is 3 that means three words formed if (position3) //Check the word combination already added in word list bool notFound true; for (int i-0; iful!List . size(); i++) if(fulllist[i]strSoFar) notFound false; //If word combination not exist then add to list if(notFound) fulllist.push_back(strSoFar); //If the position is 4 that means four words formed if (position - elements.size()) //Check the word combination already added in word list bool notFoundtrue;

for (int i-0; iful!List . size(); i++) if(fulllist[i]strSoFar) notFound false; //If word combination not exist then add to list if(notFound) fulllist.push_back (strSoFar); //If four word combination formed then call the recursive function if(loopCount - 4 && elements.size() -4) //Remove one element from List elements.erase(elements.begin)); recur_sentence (elements, e, ""); loopCount loopCount 1; return //Form Loop of the elements vector for (int i-e; i elements[position].size(); i++) recur_sentence (elements, position+1, strSoFar+elements[position][i]) int main() //Vector decLared vector<vector<string>> v(4); v[0] { "Blue" }; V[1] = { "Pig", "Dog" }; v[3] "low", "high" : //Recursive function called recur_sentence (v, e, ""): //Print the data of string formed from recursive for (int i-0; iful!List . size(); i++) function cout<<fulllist[i]<<endl;; return e

Output Screen

Blue Pig Blue Pig jump Blue Pig jump low Blue Pig jump high Blue Dog Blue Dog jump Blue Dog jump low Blue Dog jump high Pig jump Pig jump low Pig jump high Dog jump Dog jump low Dog jump high Blue Dog high . . Program finished with exit code 0 PressENTER to exit console