Imprima recursivamente todas las oraciones que se pueden formar a partir de una lista de listas de palabras

Dada una lista de listas de palabras ¿Cómo imprimir todas las oraciones posibles tomando una palabra de una lista a la vez a través de la recursividad? 

Ejemplo: 

Input: {{"you", "we"},
        {"have", "are"},
        {"sleep", "eat", "drink"}}

Output:
  you have sleep
  you have eat
  you have drink
  you are sleep
  you are eat
  you are drink
  we have sleep
  we have eat
  we have drink
  we are sleep
  we are eat
  we are drink 

Recomendamos enfáticamente minimizar su navegador y probarlo usted mismo primero.  
La idea se basa en un simple recorrido primero en profundidad. Comenzamos con cada palabra de la primera lista como la primera palabra de una oración de salida, luego recurrimos para las listas restantes.

A continuación se muestra la implementación en C++ de la idea anterior. En la implementación a continuación, la lista de entrada de la lista se considera como una array 2D. Si miramos más de cerca, podemos observar que el código está muy cerca del DFS de graph .

// C++ program to print all possible sentences from a list of word list
#include <iostream>
#include <string>
 
#define R 3
#define C 3
using namespace std;
 
// A recursive function to print all possible sentences that can be formed
// from a list of word list
void printUtil(string arr[R][C], int m, int n, string output[R])
{
    // Add current word to output array
    output[m] = arr[m][n];
 
    // If this is last word of current output sentence, then print
    // the output sentence
    if (m==R-1)
    {
        for (int i=0; i<R; i++)
           cout << output[i] << " ";
        cout << endl;
        return;
    }
 
    // Recur for next row
    for (int i=0; i<C; i++)
       if (arr[m+1][i] != "")
          printUtil(arr, m+1, i, output);
}
 
// A wrapper over printUtil()
void print(string arr[R][C])
{
   // Create an array to store sentence
   string output[R];
 
   // Consider all words for first row as starting points and
   // print all sentences
   for (int i=0; i<C; i++)
     if (arr[0][i] != "")
        printUtil(arr, 0, i, output);
}
 
// Driver program to test above functions
int main()
{
   string arr[R][C]  = {{"you", "we"},
                        {"have", "are"},
                        {"sleep", "eat", "drink"}};
 
   print(arr);
 
   return 0;
}

// Java program to print
// all possible sentences
// from a list of word list
class GFG{
 
static final int R= 3;
static final int C =3;
   
// A recursive function to
// print all possible sentences
// that can be formed 
// from a list of word list
static void printUtil(String [][]arr,
                      int m, int n,
                      String []output)
{
  // Add current word to output array
  output[m] = arr[m][n];
 
  // If this is last word of
  // current output sentence,
  // then print the output sentence
  if (m == R - 1)
  {
    for (int i = 0; i < R; i++)
      System.out.print(output[i] + " ");
    System.out.println();
    return;
  }
 
  // Recur for next row
  for (int i = 0; i < C; i++)
    if (arr[m + 1][i] != "" && m < C)
      printUtil(arr, m + 1, i, output);
}
 
// A wrapper over printUtil()
static void print(String [][]arr)
{
  // Create an array to store sentence
  String []output = new String[R];
 
  // Consider all words for first
  // row as starting points and
  // print all sentences
  for (int i = 0; i < C; i++)
    if (arr[0][i] != "")
      printUtil(arr, 0, i, output);
}
 
// Driver program to test above functions
public static void main(String[] args)
{
  String [][]arr  = {{"you", "we", ""},
                     {"have", "are", ""},
                     {"sleep", "eat", "drink"}};
  print(arr);
}
}
 
// This code is contributed by gauravrajput1

# Python program recursively print all sentences that can be
# formed from list of word lists
R = 3
C = 3
 
# A recursive function to print all possible sentences that can
# be formed from a list of word list
def printUtil(arr, m, n, output):
 
    # Add current word to output array
    output[m] = arr[m][n]
 
    # If this is last word of current output sentence, then print
    # the output sentence
    if m==R-1:
        for i in range(R):
            print (output[i],end= " ")
        print()
        return
 
    # Recur for next row
    for i in range(C):
        if arr[m+1][i] != "":
            printUtil(arr, m+1, i, output)
 
# A wrapper over printUtil
def printf(arr):
 
    # Create an array to store sentence
    output = [""] * R
 
    # Consider all words for first row as starting
    #  points and print all sentences
    for i in range(C):
        if arr[0][i] != "":
            printUtil(arr, 0, i, output)
 
# Driver program
arr = [ ["you", "we",""],
        ["have", "are",""],
        ["sleep", "eat", "drink"]]
printf(arr)
# This code is contributed by Bhavya Jain

// C# program to print
// all possible sentences
// from a list of word list
using System;
class GFG{
 
static readonly int R= 3;
static readonly int C =3;
   
// A recursive function to
// print all possible sentences
// that can be formed 
// from a list of word list
static void printUtil(String [,]arr,
                      int m, int n,
                      String []output)
{
  // Add current word to output array
  output[m] = arr[m, n];
 
  // If this is last word of
  // current output sentence,
  // then print the output sentence
  if (m == R - 1)
  {
    for (int i = 0; i < R; i++)
      Console.Write(output[i] + " ");
    Console.WriteLine();
    return;
  }
 
  // Recur for next row
  for (int i = 0; i < C; i++)
    if (arr[m + 1, i] != "" && m < C)
      printUtil(arr, m + 1, i, output);
}
 
// A wrapper over printUtil()
static void print(String [,]arr)
{
  // Create an array to store sentence
  String []output = new String[R];
 
  // Consider all words for first
  // row as starting points and
  // print all sentences
  for (int i = 0; i < C; i++)
    if (arr[0, i] != "")
      printUtil(arr, 0, i, output);
}
 
// Driver program to test above functions
public static void Main(String[] args)
{
  String [,]arr  = {{"you", "we", ""},
                    {"have", "are", ""},
                    {"sleep", "eat", "drink"}};
  print(arr);
}
}
 
// This code is contributed by gauravrajput1

<script>
 
// JavaScript program recursively print all sentences that can be
// formed from list of word lists
const R = 3
const C = 3
 
// A recursive function to print all possible sentences that can
// be formed from a list of word list
function printUtil(arr, m, n, output){
 
    // Add current word to output array
    output[m] = arr[m][n]
 
    // If this is last word of current output sentence, then print
    // the output sentence
    if(m == R - 1){
        for(let i = 0; i < R; i++)
            document.write(output[i]," ")
        document.write("</br>")
        return
    }
 
    // Recur for next row
    for(let i = 0; i < C; i++){
        if(arr[m+1][i] != "")
            printUtil(arr, m+1, i, output)
    }
}
 
// A wrapper over printUtil
function printf(arr){
 
    // Create an array to store sentence
    let output = new Array(R).fill("")
 
    // Consider all words for first row as starting
    //  points and print all sentences
    for(let i = 0; i < C; i++){
        if(arr[0][i] != "")
            printUtil(arr, 0, i, output)
    }
}
 
// Driver program
let arr = [ ["you", "we",""],
        ["have", "are",""],
        ["sleep", "eat", "drink"]]
printf(arr)
 
// This code is contributed by shinjanpatra
 
</script>

you have sleep 
you have eat 
you have drink 
you are sleep 
you are eat 
you are drink 
we have sleep 
we have eat 
we have drink 
we are sleep 
we are eat 
we are drink