# 分離偶數和奇數| 系列 3 > 原文： [https://www.geeksforgeeks.org/segregate-even-odd-numbers-set-3/](https://www.geeksforgeeks.org/segregate-even-odd-numbers-set-3/) 給定一個整數數組，請在該數組中分隔偶數和奇數。 所有的偶數應首先出現，然后是奇數。 例子： ``` Input : 1 9 5 3 2 6 7 11 Output : 2 6 5 3 1 9 7 11 Input : 1 3 2 4 7 6 9 10 Output : 2 4 6 10 7 1 9 3 ``` 我們在以下帖子中討論了兩種不同的方法： 1. [分離偶數和奇數](https://www.geeksforgeeks.org/segregate-even-and-odd-numbers/) 2. [分離偶數和奇數| 系列 2](https://www.geeksforgeeks.org/segregate-even-odd-set-2/) 本文討論的想法基于 [Lomuto 的分區方案](https://www.geeksforgeeks.org/hoares-vs-lomuto-partition-scheme-quicksort/) 1. 保持指向數組中第一個奇數元素之前位置的指針。 2. 遍歷數組，如果遇到偶數，則將其與第一個奇數元素交換。 3. 繼續遍歷。 ## C++ ```cpp // CPP code to segregate even odd // numbers in an array #include <bits/stdc++.h> using namespace std; // Function to segregate even odd numbers void arrayEvenAndOdd(int arr[], int n) { ????int i = -1, j = 0; ????int t; ????while (j != n) { ????????if (arr[j] % 2 == 0) { ????????????i++; ????????????// Swapping even and odd numbers ????????????swap(arr[i], arr[j]); ????????} ????????j++; ????} ????// Printing segregated array ????for (int i = 0; i < n; i++) ????????cout << arr[i] << " "; } // Driver code int main() { ????int arr[] = { 1, 3, 2, 4, 7, 6, 9, 10 }; ????int n = sizeof(arr) / sizeof(int); ????arrayEvenAndOdd(arr, n); ????return 0; } ``` ## Java ```java // java code to segregate even odd // numbers in an array public class GFG { ????// Function to segregate even ????// odd numbers ????static void arrayEvenAndOdd( ??????????????????int arr[], int n) ????{ ????????int i = -1, j = 0; ????????while (j != n) { ????????????if (arr[j] % 2 == 0) ????????????{ ????????????????i++; ????????????????// Swapping even and ????????????????// odd numbers ????????????????int temp = arr[i]; ????????????????arr[i] = arr[j]; ????????????????arr[j] = temp; ????????????} ????????????j++; ????????} ????????// Printing segregated array ????????for (int k = 0; k < n; k++) ?????????????System.out.print(arr[k] + " "); ????} ????// Driver code ????public static void main(String args[]) ????{ ????????int arr[] = { 1, 3, 2, 4, 7,? ????????????????????????????6, 9, 10 }; ????????int n = arr.length; ????????arrayEvenAndOdd(arr, n); ????} } // This code is contributed by Sam007 ``` ## Python3 ```py # Python3 code to segregate even odd? # numbers in an array? # Function to segregate even odd numbers? def arrayEvenAndOdd(arr,n): ????i = -1 ????j= 0 ????while (j!=n): ????????if (arr[j] % 2 ==0): ????????????i = i+1 ????????????# Swapping even and odd numbers? ????????????arr[i],arr[j] = arr[j],arr[i] ????????j = j+1 ????# Printing segregated array? ????for i in arr: ????????print (str(i) + " " ,end='') # Driver Code if __name__=='__main__': ????arr = [ 1 ,3, 2, 4, 7, 6, 9, 10] ????n = len(arr) ????arrayEvenAndOdd(arr,n) # This code was contributed by? # Yatin Gupta ``` ## C# ```cs // C# code to segregate even odd // numbers in an array using System; class GFG { ????// Function to segregate even ????// odd numbers ????static void arrayEvenAndOdd( ??????????????????int []arr, int n) ????{ ????????int i = -1, j = 0; ????????while (j != n) { ????????????if (arr[j] % 2 == 0) ????????????{ ????????????????i++; ????????????????// Swapping even and ????????????????// odd numbers ????????????????int temp = arr[i]; ????????????????arr[i] = arr[j]; ????????????????arr[j] = temp; ????????????} ????????????j++; ????????} ????????// Printing segregated array ????????for (int k = 0; k < n; k++) ????????????Console.Write(arr[k] + " "); ????} ????// Driver code???? ????static void Main() ????{ ????????int []arr = { 1, 3, 2, 4, 7,? ????????????????????????????6, 9, 10 }; ????????int n = arr.Length; ????????arrayEvenAndOdd(arr, n); ????} } // This code is contributed by Sam007 ``` ## PHP ```php <?php // PHP code to segregate even odd // numbers in an array // Function to segregate // even odd numbers function arrayEvenAndOdd($arr, $n) { ????$i = -1; ????$j = 0; ????$t; ????while ($j != $n) ????{ ????????if ($arr[$j] % 2 == 0) ????????{ ????????????$i++; ????????????// Swapping even and ????????????// odd numbers ????????????$x = $arr[$i]; ????????????$arr[$i] = $arr[$j]; ????????????$arr[$j] = $x; ????????} ????????$j++; ????} ????// Printing segregated? ????// array ????for ($i = 0; $i < $n; $i++) ????????echo $arr[$i] . " "; } ????// Driver code ????$arr = array(1, 3, 2, 4, 7, 6, 9, 10); ????$n = sizeof($arr); ????arrayEvenAndOdd($arr, $n); // This code is contributed by Anuj_67 ?> ``` **輸出**： ``` 2 4 6 10 7 1 9 3 ``` 時間復雜度：`O(n)` 輔助空間：`O(1)` * * * * * *