update translation merge-sort (#36486)

added implementation code
This commit is contained in:
Cleo Aguiar
2019-08-07 21:02:25 -03:00
committed by Randell Dawson
parent 940d3d1667
commit a9fabc4755

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@ -38,167 +38,495 @@ MergeSort(arr[], left, right):
![Merge Sort Algorithm](https://upload.wikimedia.org/wikipedia/commons/thumb/e/e6/Merge_sort_algorithm_diagram.svg/300px-Merge_sort_algorithm_diagram.svg.png) ![Merge Sort Algorithm](https://upload.wikimedia.org/wikipedia/commons/thumb/e/e6/Merge_sort_algorithm_diagram.svg/300px-Merge_sort_algorithm_diagram.svg.png)
### Properties: ### Propriedades:
* Space Complexity: O(n) * Complexidade Espacial: O(n)
* Time Complexity: O(n*log(n)). The time complexity for the Merge Sort might not be obvious from the first glance. The log(n) factor that comes in is because of the recurrence relation we have mentioned before. * Complexidade Temporal: O(n*log(n)). A complexidade temporal para o Merge Sort pode não ser óbvia desde o primeiro olhar. O fator log (n) que entra é por causa da relação de recorrência que mencionamos antes.
* Sorting In Place: No in a typical implementation * Classificação no local: não em uma implementação típica
* Stable: Yes * Estável: Sim
* Parallelizable :yes (Several parallel variants are discussed in the third edition of Cormen, Leiserson, Rivest, and Stein's Introduction to Algorithms.) * Paralelizável: Sim (Várias variantes paralelas são discutidos na terceira edição do Cormen, Leiserson, Rivest, e Introdução de Stein aos algoritmos.)
### Visualization: ### Visualização:
* <a href='https://www.cs.usfca.edu/~galles/visualization/ComparisonSort.html'>USFCA</a> * <a href='https://www.cs.usfca.edu/~galles/visualization/ComparisonSort.html'>USFCA</a>
* <a href='https://www.hackerearth.com/practice/algorithms/sorting/merge-sort/visualize/'>HackerEarth</a> * <a href='https://www.hackerearth.com/practice/algorithms/sorting/merge-sort/visualize/'>HackerEarth</a>
### Implementação em JS
### Relavant videos on freeCodeCamp YouTube channel ```js
* <a href='https://youtu.be/TzeBrDU-JaY'>Merge Sort algorithm - MyCodeSchool</a> const list = [23, 4, 42, 15, 16, 8, 3]
### Other Resources: const mergeSort = (list) =>{
* <a href='https://en.wikipedia.org/wiki/Merge_sort' target='_blank' rel='nofollow'>Wikipedia</a> if(list.length <= 1) return list;
* <a href='www.geeksforgeeks.org/merge-sort' target='_blank' rel='nofollow'>GeeksForGeeks</a> const middle = list.length / 2 ;
* <a href='https://youtu.be/sWtYJv_YXbo' target='_blank' rel='nofollow'>Merge Sort - CS50</a> const left = list.slice(0, middle);
const right = list.slice(middle, list.length);
### Implementaion in JS return merge(mergeSort(left), mergeSort(right));
}
const merge = (left, right) => {
var result = [];
while(left.length || right.length) {
if(left.length && right.length) {
if(left[0] < right[0]) {
result.push(left.shift())
} else {
result.push(right.shift())
}
} else if(left.length) {
result.push(left.shift())
} else {
result.push(right.shift())
}
}
return result;
}
console.log(mergeSort(list)) // [ 3, 4, 8, 15, 16, 23, 42 ]
``` ```
js lista const = \[23, 4, 42, 15, 16, 8, 3\] ### Implementação em C
```C
const mergeSort = (lista) => { if (list.length <= 1) lista de retorno; const middle = list.length / 2; const left = list.slice (0, middle); const right = list.slice (meio, list.length); mesclagem de retorno (mergeSort (esquerda), mergeSort (direita)); } #include<stdlib.h>
#include<stdio.h>
const merge = (esquerda, direita) => { var result = \[\]; while (left.length || right.length) { if (left.length && right.length) { if (esquerda \[0\] <direita \[0\]) { result.push (left.shift ()) } outro { result.push (right.shift ()) } } else if (left.length) { result.push (left.shift ()) } outro { result.push (right.shift ()) } } resultado de retorno; } void merge(int arr[], int l, int m, int r)
{
console.log (mergeSort (list)) // \[3, 4, 8, 15, 16, 23, 42\] int i, j, k;
``` int n1 = m - l + 1;
### Implementation in C int n2 = r - m;
```
C int L[n1], R[n2];
# incluir for (i = 0; i < n1; i++)
L[i] = arr[l + i];
# incluir for (j = 0; j < n2; j++)
R[j] = arr[m + 1+ j];
mesclagem vazia (int arr \[\], int l, int m, int r) { int i, j, k; int n1 = m - l + 1; int n2 = r - m; i = 0;
``` j = 0;
int L[n1], R[n2]; k = l;
while (i < n1 && j < n2)
for (i = 0; i < n1; i++) {
L[i] = arr[l + i]; if (L[i] <= R[j])
for (j = 0; j < n2; j++) {
R[j] = arr[m + 1+ j]; arr[k] = L[i];
i = 0; i++;
j = 0; }
k = l; else
while (i < n1 && j < n2) {
{ arr[k] = R[j];
if (L[i] <= R[j]) j++;
}
k++;
}
while (i < n1)
{ {
arr[k] = L[i]; arr[k] = L[i];
i++; i++;
k++;
} }
else
while (j < n2)
{ {
arr[k] = R[j]; arr[k] = R[j];
j++; j++;
k++;
} }
k++; }
}
void mergeSort(int arr[], int l, int r)
{
while (i < n1) if (l < r)
{ {
arr[k] = L[i]; int m = l+(r-l)/2;
i++;
k++;
} mergeSort(arr, l, m);
mergeSort(arr, m+1, r);
while (j < n2)
{ merge(arr, l, m, r);
arr[k] = R[j]; }
j++; }
k++; void printArray(int A[], int size)
} {
int i;
for (i=0; i < size; i++)
printf("%d ", A[i]);
printf("\n");
}
int main()
{
int arr[] = {12, 11, 13, 5, 6, 7};
int arr_size = sizeof(arr)/sizeof(arr[0]);
printf("Given array is \n");
printArray(arr, arr_size);
mergeSort(arr, 0, arr_size - 1);
printf("\nSorted array is \n");
printArray(arr, arr_size);
return 0;
``` ```
### Implementação em C++
Vamos considerar o array A = {2,5,7,8,9,12,13}
e array B = {3,5,6,9,15} e queremos que o array C esteja em ordem crescente também.
```cpp
void mergesort(int A[],int size_a,int B[],int size_b,int C[])
{
int token_a,token_b,token_c;
for(token_a=0, token_b=0, token_c=0; token_a<size_a && token_b<size_b; )
{
if(A[token_a]<=B[token_b])
C[token_c++]=A[token_a++];
else
C[token_c++]=B[token_b++];
}
if(token_a<size_a)
{
while(token_a<size_a)
C[token_c++]=A[token_a++];
}
else
{
while(token_b<size_b)
C[token_c++]=B[token_b++];
}
void merge(int arr[], int l, int m, int r)
{
int i, j, k;
int n1 = m - l + 1;
int n2 = r - m;
int L[n1], R[n2];
for (i = 0; i < n1; i++)
L[i] = arr[l + i];
for (j = 0; j < n2; j++)
R[j] = arr[m + 1+ j];
i = 0;
j = 0;
k = l;
while (i < n1 && j < n2)
{
if (L[i] <= R[j])
{
arr[k] = L[i];
i++;
}
else
{
arr[k] = R[j];
j++;
}
k++;
}
while (i < n1)
{
arr[k] = L[i];
i++;
k++;
}
while (j < n2)
{
arr[k] = R[j];
j++;
k++;
}
}
void mergeSort(int arr[], int l, int r)
{
if (l < r)
{
int m = l+(r-l)/2;
mergeSort(arr, l, m);
mergeSort(arr, m+1, r);
merge(arr, l, m, r);
}
}
```
### Implementação em Python
```python
def merge(left,right,compare):
result = []
i,j = 0,0
while (i < len(left) and j < len(right)):
if compare(left[i],right[j]):
result.append(left[i])
i += 1
else:
result.append(right[j])
j += 1
while (i < len(left)):
result.append(left[i])
i += 1
while (j < len(right)):
result.append(right[j])
j += 1
return result
def merge_sort(arr, compare = lambda x, y: x < y):
#Used lambda function to sort array in both(increasing and decresing) order.
#By default it sorts array in increasing order
if len(arr) < 2:
return arr[:]
else:
middle = len(arr) // 2
left = merge_sort(arr[:middle], compare)
right = merge_sort(arr[middle:], compare)
return merge(left, right, compare)
arr = [2,1,4,5,3]
print(merge_sort(arr))
```
### Implementação em Java
```java
public class mergesort {
public static int[] mergesort(int[] arr,int lo,int hi) {
if(lo==hi) {
int[] ba=new int[1];
ba[0]=arr[lo];
return ba;
}
int mid=(lo+hi)/2;
int arr1[]=mergesort(arr,lo,mid);
int arr2[]=mergesort(arr,mid+1,hi);
return merge(arr1,arr2);
}
public static int[] merge(int[] arr1,int[] arr2) {
int i=0,j=0,k=0;
int n=arr1.length;
int m=arr2.length;
int[] arr3=new int[m+n];
while(i<n && j<m) {
if(arr1[i]<arr2[j]) {
arr3[k]=arr1[i];
i++;
}
else {
arr3[k]=arr2[j];
j++;
}
k++;
}
while(i<n) {
arr3[k]=arr1[i];
i++;
k++;
}
while(j<m) {
arr3[k]=arr2[j];
j++;
k++;
}
return arr3;
}
public static void main(String[] args) {
// TODO Auto-generated method stub
int arr[]= {2,9,8,3,6,4,10,7};
int[] so=mergesort(arr,0,arr.length-1);
for(int i=0;i<arr.length;i++)
System.out.print(so[i]+" ");
}
} }
void mergeSort (int arr \[\], int l, int r) { if (l <r) {
int m = l + (rl) / 2;
```
mergeSort(arr, l, m);
mergeSort(arr, m+1, r);
merge(arr, l, m, r);
}
``` ```
### Exemplo em Java
```java
public class mergesort {
public static int[] mergesort(int[] arr, int lo, int hi) {
if (lo == hi) {
int[] ba = new int[1];
ba[0] = arr[lo];
return ba;
}
int mid = (lo + hi) / 2;
int arr1[] = mergesort(arr, lo, mid);
int arr2[] = mergesort(arr, mid + 1, hi);
return merge(arr1, arr2);
}
} void printArray (int A \[\], tamanho int) { int i; para (i = 0; i <tamanho; i ++) printf ("% d", A \[i\]); printf ("\\ n"); } int main () { int arr \[\] = {12, 11, 13, 5, 6, 7}; int arr\_size = sizeof (arr) / sizeof (arr \[0\]); public static int[] merge(int[] arr1, int[] arr2) {
``` int i = 0, j = 0, k = 0;
printf("Given array is \n"); int n = arr1.length;
printArray(arr, arr_size); int m = arr2.length;
int[] arr3 = new int[m + n];
mergeSort(arr, 0, arr_size - 1); while (i < n && j < m) {
if (arr1[i] < arr2[j]) {
printf("\nSorted array is \n"); arr3[k] = arr1[i];
printArray(arr, arr_size); i++;
return 0; } else {
``` arr3[k] = arr2[j];
j++;
``` }
### Implementation in C++ k++;
}
Let us consider array A = {2,5,7,8,9,12,13} while (i < n) {
and array B = {3,5,6,9,15} and we want array C to be in ascending order as well. arr3[k] = arr1[i];
``` i++;
k++;
c ++ void mergesort (int A \[\], int tamanho _a, int B \[\], int tamanho_ b, int C \[\]) { token int _, token_ b, token _c; para (token_ a = 0, token _b = 0, token_ c = 0; token _a_ _um && token _b__ __b; ) { if (A \[token _a\] <= B \[token_ b\]) C \[token _c ++\] = A \[token_ um ++\]; outro C \[token _c ++\] = B \[token_ b ++\]; }__ }
``` while (j < m) {
if(token_a<size_a) arr3[k] = arr2[j];
{ j++;
while(token_a<size_a) k++;
C[token_c++]=A[token_a++]; }
} return arr3;
else }
{
while(token_b<size_b)
C[token_c++]=B[token_b++];
}
```
public static void main(String[] args) {
int arr[] = {2, 9, 8, 3, 6, 4, 10, 7};
int[] so = mergesort(arr, 0, arr.length - 1);
for (int i = 0; i < arr.length; i++)
System.out.print(so[i] + " ");
}
} }
``` ```
### Implementation in Python
### Implementação em MATLAB
```matlab
a = [9,4,7,3,8,5,1,6,2];
[sorted] = mergeSort(a);
function [sorted] = mergeSort(unsorted)
len = length(unsorted);
if len == 1
sorted = unsorted;
return;
end
mid = ceil((len)/2);
left = mergeSort(unsorted(1:mid));
right = mergeSort(unsorted(mid+1:end));
sorted = mergeLR(left, right);
end
function [sorted] = mergeLR(left, right)
sorted = [left right]; % add two splited array together
j = 1; % index for 'sorted'
k = 1; % index for 'left'
for i = 1:1:length(right)
% going through every element of the 'right'
if right(i) < left(k)
sorted(j) = right(i); % move the 'right' element before
sorted(j+1:(j+length(left(k:end)))) = left(k:end); % shift the left elemts
j = j+1;
else
while (k <= length(left)) && (right(i) > left(k))
k = k+1;
j = j+1;
end
sorted(j) = right(i);
sorted(j+1:(j+length(left(k:end)))) = left(k:end);
j = j+1;
end
end
end
``` ```
python temp = None def merge (arr, esquerda, direita): temp global, inversões mid = (esquerda + direita) // 2 para eu na faixa (esquerda, direita + 1): temp \[i\] = arr \[i\] ### Implementação em Java
```Java
class MergeSort
{
void merge(int arr[], int l, int m, int r)
{
int n1 = m - l + 1;
int n2 = r - m;
int L[] = new int [n1];
int R[] = new int [n2];
for (int i=0; i<n1; ++i)
L[i] = arr[l + i];
for (int j=0; j<n2; ++j)
R[j] = arr[m + 1+ j];
int i = 0, j = 0;
int k = l;
while (i < n1 && j < n2)
{
if (L[i] <= R[j])
{
arr[k] = L[i];
i++;
}
else
{
arr[k] = R[j];
j++;
}
k++;
}
while (i < n1)
{
arr[k] = L[i];
i++;
k++;
}
while (j < n2)
{
arr[k] = R[j];
j++;
k++;
}
}
void sort(int arr[], int l, int r)
{
if (l < r)
{
int m = (l+r)/2;
sort(arr, l, m);
sort(arr , m+1, r);
merge(arr, l, m, r);
}
}
static void printArray(int arr[])
{
int n = arr.length;
for (int i=0; i<n; ++i)
System.out.print(arr[i] + " ");
System.out.println();
}
public static void main(String args[])
{
int arr[] = {12, 11, 13, 5, 6, 7};
System.out.println("Given Array");
printArray(arr);
MergeSort ob = new MergeSort();
ob.sort(arr, 0, arr.length-1);
System.out.println("\n The Sorted array is : ");
printArray(arr);
}
}
``` ```
k, L, R = left, left, mid + 1
while L <= mid and R <= right: ### Vídeos relevantes no canal do YouTube freeCodeCamp
if temp[L] <= temp[R]: * <a href='https://youtu.be/TzeBrDU-JaY'>Merge Sort algorithm - MyCodeSchool</a>
arr[k] = temp[L]
L += 1
else:
arr[k] = temp[R]
R += 1
k += 1
while L <= mid: ### Outros recursos:
arr[k] = temp[L] * <a href='https://en.wikipedia.org/wiki/Merge_sort' target='_blank' rel='nofollow'>Wikipedia</a>
L += 1 * <a href='www.geeksforgeeks.org/merge-sort' target='_blank' rel='nofollow'>GeeksForGeeks</a>
k += 1 * <a href='https://youtu.be/sWtYJv_YXbo' target='_blank' rel='nofollow'>Merge Sort - CS50</a>
while R <= right:
arr[k] = temp[R]
R += 1
k += 1
```
def merge\_sort (arr, esquerda, direita): se saiu> = certo: Retorna
```
mid = (left + right) // 2
merge_sort(arr, left, mid)
merge_sort(arr, mid + 1, right)
merge(arr, left, right)
```
arr = \[1,6,3,1,8,4,2,9,3\] temp = \[Nenhum para \_ no intervalo (len (arr))\] merge\_sort (arr, 0, len (arr) - 1) imprimir (arr, inversões) \`\` \`