Dadas dos arrays ordenadas A y B, genere todas las arrays posibles de modo que el primer elemento se tome de A, luego de B, luego de A y así sucesivamente en orden creciente hasta que se agoten las arrays. Las arrays generadas deben terminar con un elemento de B.
Por ejemplo
A = {10, 15, 25}
B = {1, 5, 20, 30}
The resulting arrays are:
10 20
10 20 25 30
10 30
15 20
15 20 25 30
15 30
25 30
Le recomendamos encarecidamente que minimice su navegador y que pruebe esto usted mismo primero.
La idea es usar la recursividad. En la función recursiva, se pasa una bandera para indicar si el elemento actual en la salida debe tomarse de ‘A’ o ‘B’. A continuación se muestra la implementación de C++.
C++
#include<bits/stdc++.h>
using namespace std;
void printArr(int arr[], int n);
/* Function to generates and prints all sorted arrays from alternate elements of
'A[i..m-1]' and 'B[j..n-1]'
If 'flag' is true, then current element is to be included from A otherwise
from B.
'len' is the index in output array C[]. We print output array each time
before including a character from A only if length of output array is
greater than 0. We try than all possible combinations */
void generateUtil(int A[], int B[], int C[], int i, int j, int m, int n,
int len, bool flag)
{
if (flag) // Include valid element from A
{
// Print output if there is at least one 'B' in output array 'C'
if (len)
printArr(C, len+1);
// Recur for all elements of A after current index
for (int k = i; k < m; k++)
{
if (!len)
{
/* this block works for the very first call to include
the first element in the output array */
C[len] = A[k];
// don't increment lem as B is included yet
generateUtil(A, B, C, k+1, j, m, n, len, !flag);
}
else /* include valid element from A and recur */
{
if (A[k] > C[len])
{
C[len+1] = A[k];
generateUtil(A, B, C, k+1, j, m, n, len+1, !flag);
}
}
}
}
else /* Include valid element from B and recur */
{
for (int l = j; l < n; l++)
{
if (B[l] > C[len])
{
C[len+1] = B[l];
generateUtil(A, B, C, i, l+1, m, n, len+1, !flag);
}
}
}
}
/* Wrapper function */
void generate(int A[], int B[], int m, int n)
{
int C[m+n]; /* output array */
generateUtil(A, B, C, 0, 0, m, n, 0, true);
}
// A utility function to print an array
void printArr(int arr[], int n)
{
for (int i = 0; i < n; i++)
cout << arr[i] << " ";
cout << endl;
}
// Driver program
int main()
{
int A[] = {10, 15, 25};
int B[] = {5, 20, 30};
int n = sizeof(A)/sizeof(A[0]);
int m = sizeof(B)/sizeof(B[0]);
generate(A, B, n, m);
return 0;
}
Java
class GenerateArrays {
/* Function to generates and prints all sorted arrays from alternate
elements of 'A[i..m-1]' and 'B[j..n-1]'
If 'flag' is true, then current element is to be included from A
otherwise from B.
'len' is the index in output array C[]. We print output array
each time before including a character from A only if length of
output array is greater than 0. We try than all possible
combinations */
void generateUtil(int A[], int B[], int C[], int i, int j, int m, int n,
int len, boolean flag)
{
if (flag) // Include valid element from A
{
// Print output if there is at least one 'B' in output array 'C'
if (len != 0)
printArr(C, len + 1);
// Recur for all elements of A after current index
for (int k = i; k < m; k++)
{
if (len == 0)
{
/* this block works for the very first call to include
the first element in the output array */
C[len] = A[k];
// don't increment lem as B is included yet
generateUtil(A, B, C, k + 1, j, m, n, len, !flag);
}
/* include valid element from A and recur */
else if (A[k] > C[len])
{
C[len + 1] = A[k];
generateUtil(A, B, C, k + 1, j, m, n, len + 1, !flag);
}
}
}
/* Include valid element from B and recur */
else
{
for (int l = j; l < n; l++)
{
if (B[l] > C[len])
{
C[len + 1] = B[l];
generateUtil(A, B, C, i, l + 1, m, n, len + 1, !flag);
}
}
}
}
/* Wrapper function */
void generate(int A[], int B[], int m, int n)
{
int C[] = new int[m + n];
/* output array */
generateUtil(A, B, C, 0, 0, m, n, 0, true);
}
// A utility function to print an array
void printArr(int arr[], int n)
{
for (int i = 0; i < n; i++)
System.out.print(arr[i] + " ");
System.out.println("");
}
public static void main(String[] args)
{
GenerateArrays generate = new GenerateArrays();
int A[] = {10, 15, 25};
int B[] = {5, 20, 30};
int n = A.length;
int m = B.length;
generate.generate(A, B, n, m);
}
}
// This code has been contributed by Mayank Jaiswal
Python3
# A utility function to print an array def printArr(arr,n): for i in range(n): print(arr[i] , " ",end="") print() ''' Function to generates and prints all sorted arrays from alternate elements of 'A[i..m-1]' and 'B[j..n-1]' If 'flag' is true, then current element is to be included from A otherwise from B. 'len' is the index in output array C[]. We print output array each time before including a character from A only if length of output array is greater than 0. We try than all possible combinations ''' def generateUtil(A,B,C,i,j,m,n,len,flag): if (flag): # Include valid element from A # Print output if there is at # least one 'B' in output array 'C' if (len): printArr(C, len+1) # Recur for all elements of # A after current index for k in range(i,m): if ( not len): ''' this block works for the very first call to include the first element in the output array ''' C[len] = A[k] # don't increment lem # as B is included yet generateUtil(A, B, C, k+1, j, m, n, len, not flag) else: # include valid element from A and recur if (A[k] > C[len]): C[len+1] = A[k] generateUtil(A, B, C, k+1, j, m, n, len+1, not flag) else: # Include valid element from B and recur for l in range(j,n): if (B[l] > C[len]): C[len+1] = B[l] generateUtil(A, B, C, i, l+1, m, n, len+1, not flag) # Wrapper function def generate(A,B,m,n): C=[] #output array for i in range(m+n+1): C.append(0) generateUtil(A, B, C, 0, 0, m, n, 0, True) # Driver program A = [10, 15, 25] B = [5, 20, 30] n = len(A) m = len(B) generate(A, B, n, m) # This code is contributed # by Anant Agarwal.
C#
// C# Program to generate all possible
// sorted arrays from alternate elements
// of two given sorted arrays
using System;
class GenerateArrays {
/* Function to generates and prints
all sorted arrays from alternate
elements of 'A[i..m-1]' and 'B[j..n-1]'
If 'flag' is true, then current element
is to be included from A otherwise
from B.
'len' is the index in output array
C[]. We print output array each
time before including a character
from A only if length of output array
is greater than 0. We try than all
possible combinations */
public virtual void generateUtil(int[] A, int[] B,
int[] C, int i,
int j, int m, int n,
int len, bool flag) {
// Include valid
// element from A
if (flag)
{
// Print output if there is
// at least one 'B' in
// output array 'C'
if (len != 0) {
printArr(C, len + 1);
}
// Recur for all elements
// of A after current index
for (int k = i; k < m; k++) {
if (len == 0) {
/* this block works for the
very first call to include
the first element in the
output array */
C[len] = A[k];
// don't increment lem
// as B is included yet
generateUtil(A, B, C, k + 1, j,
m, n, len, !flag);
}
// include valid element
// from A and recur
else if (A[k] > C[len]) {
C[len + 1] = A[k];
generateUtil(A, B, C, k + 1, j,
m, n, len + 1, !flag);
}
}
}
// Include valid element
// from B and recur
else {
for (int l = j; l < n; l++) {
if (B[l] > C[len]) {
C[len + 1] = B[l];
generateUtil(A, B, C, i, l + 1,
m, n, len + 1, !flag);
}
}
}
}
// Wrapper function
public virtual void generate(int[] A, int[] B,
int m, int n) {
int[] C = new int[m + n];
// output array
generateUtil(A, B, C, 0, 0, m, n, 0, true);
}
// A utility function to print an array
public virtual void printArr(int[] arr, int n) {
for (int i = 0; i < n; i++) {
Console.Write(arr[i] + " ");
}
Console.WriteLine("");
}
// Driver Code
public static void Main(string[] args) {
GenerateArrays generate = new GenerateArrays();
int[] A = new int[] {10, 15, 25};
int[] B = new int[] {5, 20, 30};
int n = A.Length;
int m = B.Length;
generate.generate(A, B, n, m);
}
}
// This code is contributed by Shrikant13
PHP
<?php
/* Function to generates and prints all
sorted arrays from alternate elements of
'A[i..m-1]' and 'B[j..n-1]'
If 'flag' is true, then current element
is to be included from A otherwise from B.
'len' is the index in output array C[].
We print output array each time before
including a character from A only if length
of output array is greater than 0. We try
than all possible combinations */
function generateUtil(&$A, &$B, &$C, $i, $j,
$m, $n, $len, $flag)
{
if ($flag) // Include valid element from A
{
// Print output if there is at least
// one 'B' in output array 'C'
if ($len)
printArr($C, $len + 1);
// Recur for all elements of A
// after current index
for ($k = $i; $k < $m; $k++)
{
if (!$len)
{
/* this block works for the very
first call to include the first
element in the output array */
$C[$len] = $A[$k];
// don't increment lem as B
// is included yet
generateUtil($A, $B, $C, $k + 1,
$j, $m, $n, $len, !$flag);
}
else /* include valid element
from A and recur */
{
if ($A[$k] > $C[$len])
{
$C[$len + 1] = $A[$k];
generateUtil($A, $B, $C, $k + 1, $j,
$m, $n, $len + 1, !$flag);
}
}
}
}
else /* Include valid element
from B and recur */
{
for ($l = $j; $l < $n; $l++)
{
if ($B[$l] > $C[$len])
{
$C[$len + 1] = $B[$l];
generateUtil($A, $B, $C, $i, $l + 1,
$m, $n, $len + 1, !$flag);
}
}
}
}
/* Wrapper function */
function generate(&$A, &$B, $m, $n)
{
$C = array_fill(0, ($m + $n), NULL); /* output array */
generateUtil($A, $B, $C, 0, 0, $m, $n, 0, true);
}
// A utility function to print an array
function printArr(&$arr, $n)
{
for ($i = 0; $i < $n; $i++)
echo $arr[$i] . " ";
echo "\n";
}
// Driver Code
$A = array(10, 15, 25);
$B = array(5, 20, 30);
$n = sizeof($A);
$m = sizeof($B);
generate($A, $B, $n, $m);
// This code is contributed by ChitraNayal
?>
Javascript
<script>
/*
* Function to generates and prints all sorted arrays from alternate elements of
* 'A[i..m-1]' and 'B[j..n-1]' If 'flag' is true, then current element is to be
* included from A otherwise from B. 'len' is the index in output array C. We
* print output array each time before including a character from A only if
* length of output array is greater than 0. We try than all possible
* combinations
*/
function generateUtil(A , B , C , i , j , m , n , len, flag) {
if (flag) // Include valid element from A
{
// Print output if there is at least one 'B' in output array 'C'
if (len != 0)
printArr(C, len + 1);
// Recur for all elements of A after current index
for (var k = i; k < m; k++) {
if (len == 0) {
/*
* this block works for the very first call to include the first element in the
* output array
*/
C[len] = A[k];
// don't increment lem as B is included yet
generateUtil(A, B, C, k + 1, j, m, n, len, !flag);
}
/* include valid element from A and recur */
else if (A[k] > C[len]) {
C[len + 1] = A[k];
generateUtil(A, B, C, k + 1, j, m, n, len + 1, !flag);
}
}
}
/* Include valid element from B and recur */
else {
for (var l = j; l < n; l++) {
if (B[l] > C[len]) {
C[len + 1] = B[l];
generateUtil(A, B, C, i, l + 1, m, n, len + 1, !flag);
}
}
}
}
/* Wrapper function */
function generate(A , B , m , n) {
var C = Array(m + n).fill(0);
/* output array */
generateUtil(A, B, C, 0, 0, m, n, 0, true);
}
// A utility function to print an array
function printArr(arr , n) {
for (i = 0; i < n; i++)
document.write(arr[i] + " ");
document.write("<br/>");
}
var A = [ 10, 15, 25 ];
var B = [ 5, 20, 30 ];
var n = A.length;
var m = B.length;
generate(A, B, n, m);
// This code contributed by gauravrajput1
</script>
Producción:
10 20 10 20 25 30 10 30 15 20 15 20 25 30 15 30 25 30
Complejidad del tiempo: O(N 2 )
Espacio auxiliar: O(M+N)
Este artículo es una contribución de Gaurav Ahirwar . Escriba comentarios si encuentra algo incorrecto o si desea compartir más información sobre el tema tratado anteriormente\
Publicación traducida automáticamente
Artículo escrito por GeeksforGeeks-1 y traducido por Barcelona Geeks. The original can be accessed here. Licence: CCBY-SA