搜索，插入和删除未排序的数组

在此后搜索中，讨论了未排序数组中的插入和删除操作。

搜索操作

在未排序的数组中，搜索操作可以通过从第一个元素到最后一个元素的线性遍历来执行。

C++

// C++ program to implement linear
// search in unsorted array
#include
using namespace std;
 
// Function to implement search operation
int findElement(int arr[], int n,
                int key)
{
    int i;
    for (i = 0; i < n; i++)
        if (arr[i] == key)
            return i;
 
    return -1;
}
 
// Driver Code
int main()
{
    int arr[] = {12, 34, 10, 6, 40};
    int n = sizeof(arr) / sizeof(arr[0]);
 
    // Using a last element as search element
    int key = 40;
    int position = findElement(arr, n, key);
 
    if (position == - 1)
        cout << "Element not found";
    else
        cout << "Element Found at Position: "
             << position + 1;
 
    return 0;
}
 
// This code is contributed
// by Akanksha Rai

C

// C program to implement linear
// search in unsorted array
#include
 
// Function to implement search operation
int findElement(int arr[], int n,
                int key)
{
    int i;
    for (i = 0; i < n; i++)
        if (arr[i] == key)
            return i;
 
    return -1;
}
 
// Driver Code
int main()
{
    int arr[] = {12, 34, 10, 6, 40};
    int n = sizeof(arr) / sizeof(arr[0]);
 
    // Using a last element as search element
    int key = 40;
    int position = findElement(arr, n, key);
 
    if (position == - 1)
        printf("Element not found");
    else
        printf("Element Found at Position: %d", position + 1 );
 
    return 0;
}

Java

// Java program to implement linear
// search in unsorted arrays
 
class Main
{
    // Function to implement
    // search operation
    static int findElement(int arr[], int n,
                           int key)
    {
        for (int i = 0; i < n; i++)
            if (arr[i] == key)
                return i;
      
        return -1;
    }
      
    // Driver Code
    public static void main(String args[])
    {
        int arr[] = {12, 34, 10, 6, 40};
        int n = arr.length;
      
        // Using a last element as search element
        int key = 40;
        int position = findElement(arr, n, key);
      
        if (position == - 1)
            System.out.println("Element not found");
        else
            System.out.println("Element Found at Position: "
                                + (position + 1));
    }
}

Python

# Python program for searching in
# unsorted array
 
def findElement(arr, n, key):
    for i in range (n):
        if (arr[i] == key):
            return i
    return -1
  
arr = [12, 34, 10, 6, 40]
key = 40
n = len(arr)
  
#search operation
index = findElement(arr, n, key)
if index != -1:
    print ("element found at position: " + str(index + 1 ))
else:
    print ("element not found")
     
# Thanks to Aditi Sharma for contributing
# this code

C#

// C# program to implement linear
// search in unsorted arrays
using System;
 
class main
{
    // Function to implement
    // search operation
    static int findElement(int []arr, int n,
                           int key)
    {
        for (int i = 0; i < n; i++)
            if (arr[i] == key)
                return i;
     
        return -1;
    }
     
    // Driver Code
    public static void Main()
    {
        int []arr = {12, 34, 10, 6, 40};
        int n = arr.Length;
     
        // Using a last element as
        // search element
        int key =40;
        int position = findElement(arr,n,key);
     
        if (position == - 1)
        Console.WriteLine("Element not found");
        else
        Console.WriteLine("Element Found at Position: "
                            + (position+1));
    }
}
 
//  This code is contributed by vt_m.

Javascript

 
// Javascript program to implement linear
// search in unsorted array
 
 
// Function to implement search operation
function findElement( arr, n, key)
{
    let i;
    for (i = 0; i < n; i++)
        if (arr[i] == key)
            return i;
 
    return -1;
}
 
 
     
    // Driver program
     
    let arr = [12, 34, 10, 6, 40];
    let n = arr.length;
 
    // Using a last element as search element
    let key = 40;
    let position = findElement(arr, n, key);
 
    if (position == - 1)
        document.write("Element not found");
    else
        document.write("Element Found at Position: "
             + (position + 1));
     
     

---

输出：

Element Found at Position: 5

在末尾插入

在未排序的数组中，插入操作比已排序的数组要快，因为我们不必关心元素放置的位置。

C++

// C++ program to implement insert
// operation in an unsorted array.
#include 
using namespace std;
 
// Inserts a key in arr[] of given capacity.
// n is current size of arr[]. This
// function returns n + 1 if insertion
// is successful, else n.
int insertSorted(int arr[], int n,
                int key,
                int capacity)
{
 
    // Cannot insert more elements if n is
    // already more than or equal to capcity
    if (n >= capacity)
    return n;
 
    arr[n] = key;
 
    return (n + 1);
}
 
// Driver Code
int main()
{
    int arr[20] = {12, 16, 20, 40, 50, 70};
    int capacity = sizeof(arr) / sizeof(arr[0]);
    int n = 6;
    int i, key = 26;
 
    cout << "\n Before Insertion: ";
    for (i = 0; i < n; i++)
        cout << arr[i]<< " ";
 
    // Inserting key
    n = insertSorted(arr, n, key, capacity);
 
    cout << "\n After Insertion: ";
    for (i = 0; i < n; i++)
        cout << arr[i] << " ";
 
    return 0;
}
 
// This code is contributed by SHUBHAMSINGH10

C

// C program to implement insert
// operation in an unsorted array.
#include
 
// Inserts a key in arr[] of given capacity.
// n is current size of arr[]. This
// function returns n + 1 if insertion
// is successful, else n.
int insertSorted(int arr[], int n,
                 int key,
                 int capacity)
{
 
    // Cannot insert more elements if n is
    // already more than or equal to capcity
    if (n >= capacity)
       return n;
 
    arr[n] = key;
 
    return (n + 1);
}
 
// Driver Code
int main()
{
    int arr[20] = {12, 16, 20, 40, 50, 70};
    int capacity = sizeof(arr) / sizeof(arr[0]);
    int n = 6;
    int i, key = 26;
 
    printf("\n Before Insertion: ");
    for (i = 0; i < n; i++)
        printf("%d  ", arr[i]);
 
    // Inserting key
    n = insertSorted(arr, n, key, capacity);
 
    printf("\n After Insertion: ");
    for (i = 0; i < n; i++)
        printf("%d  ",arr[i]);
 
    return 0;
}

Java

// Java program to implement insert
// operation in an unsorted array.
 
class Main
{
    // Function to insert a given key in
    // the array. This function returns n+1
    // if insertion is successful, else n.
    static int insertSorted(int arr[], int n,
                            int key,
                            int capacity)
    {
 
        // Cannot insert more elements if n
        // is already more than or equal to
        // capcity
        if (n >= capacity)
           return n;
      
        arr[n] = key;
      
        return (n + 1);
    }
      
    // Driver Code
    public static void main (String[] args)
    {  
        int[] arr = new int[20];
        arr[0] = 12;
        arr[1] = 16;
        arr[2] = 20;
        arr[3] = 40;
        arr[4] = 50;
        arr[5] = 70;
        int capacity = 20;
        int n = 6;
        int i, key = 26;
      
        System.out.print("Before Insertion: ");
        for (i = 0; i < n; i++)
            System.out.print(arr[i]+" ");
      
        // Inserting key
        n = insertSorted(arr, n, key, capacity);
      
        System.out.print("\n After Insertion: ");
        for (i = 0; i < n; i++)
            System.out.print(arr[i]+" ");
    }
}

Python

# Python program for inserting
# an element in an unsorted array
 
# method to insert element
def insert(arr, element):
    arr.append(element)
 
# declaring array and key to insert
arr = [12, 16, 20, 40, 50, 70]
key = 26
  
# array before inserting an element
print ("Before Inserting: ")
print (arr)
  
# array after Inserting element
insert(arr, key)
print("After Inserting: ")
print (arr)
 
# Thanks to Aditi Sharma for contributing
# this code   

C＃

// C# program to implement insert
// operation in an unsorted array.
using System;
 
class main
{
     
    // Function to insert a given
    // key in the array. This
    // function  returns n + 1
    // if insertion is successful,
    // else n.
    static int insertSorted(int []arr, int n,
                            int key,
                            int capacity)
    {
         
        // Cannot insert more elements
        // if n is already more than
        // or equal to capcity
        if (n >= capacity)
        return n;
     
        arr[n] = key;
        return (n + 1);
    }
     
    // Driver Code
    public static void Main ()
    {
        int[] arr = new int[20];
        arr[0] = 12;
        arr[1] = 16;
        arr[2] = 20;
        arr[3] = 40;
        arr[4] = 50;
        arr[5] = 70;
        int capacity = 20;
        int n = 6;
        int i, key = 26;
     
        Console.Write("Before Insertion: ");
        for (i = 0; i < n; i++)
            Console.Write(arr[i]+" ");
            Console.WriteLine();
     
        // Inserting key
        n = insertSorted(arr, n, key, capacity);
     
        Console.Write("After Insertion: ");
        for (i = 0; i < n; i++)
            Console.Write(arr[i]+" ");
             
    }
}
 
// This code is contributed by vt_m.

的PHP

= $capacity)
        return $n;
 
    array_push($arr, $key);
 
    return ($n + 1);
}
 
// Driver Code
 
$arr = array(12, 16, 20, 40, 50, 70);
$capacity = 20;
$n = 6;
$key = 26;
 
echo "Before Insertion: ";
for ($i = 0; $i < $n; $i++)
    echo $arr[$i] . " ";
 
// Inserting key
$n = insertSorted($arr, $n,
                  $key, $capacity);
 
echo "\nAfter Insertion: ";
for ($i = 0; $i < $n; $i++)
    echo $arr[$i] . " ";
     
// This code is contributed by
// Rajput-Ji
?>

输出：

Before Insertion: 12 16 20 40 50 70 
After Insertion: 12 16 20 40 50 70 26 

删除操作

在删除操作中，使用线性搜索来搜索要删除的元素，然后执行删除操作，然后移动这些元素。

C++

// C++ program to implement delete operation in a
// unsorted array
#include 
using namespace std;
 
// To search a key to be deleted
int findElement(int arr[], int n,
                int key);
 
// Function to delete an element
int deleteElement(int arr[], int n,
                int key)
{
    // Find position of element to be deleted
    int pos = findElement(arr, n, key);
 
    if (pos == - 1)
    {
        cout << "Element not found";
        return n;
    }
 
    // Deleting element
    int i;
    for (i = pos; i < n - 1; i++)
        arr[i] = arr[i + 1];
 
    return n - 1;
}
 
// Function to implement search operation
int findElement(int arr[], int n, int key)
{
    int i;
    for (i = 0; i < n; i++)
        if (arr[i] == key)
            return i;
 
    return - 1;
}
 
// Driver code
int main()
{
    int i;
    int arr[] = {10, 50, 30, 40, 20};
 
    int n = sizeof(arr) / sizeof(arr[0]);
    int key = 30;
 
    cout << "Array before deletion\n";
    for (i = 0; i < n; i++)
    cout << arr[i] <<" " ;
 
    n = deleteElement(arr, n, key);
 
    cout << "\n\nArray after deletion\n";
    for (i = 0; i < n; i++)
    cout << arr[i] << " ";
 
    return 0;
}
 
// This code is contributed by shubhamsingh10

C

// C program to implement delete operation in a
// unsorted array
#include
 
// To search a key to be deleted
int findElement(int arr[], int n,
                int key);
 
// Function to delete an element
int deleteElement(int arr[], int n,
                  int key)
{
    // Find position of element to be deleted
    int pos = findElement(arr, n, key);
 
    if (pos == - 1)
    {
        printf("Element not found");
        return n;
    }
 
    // Deleting element
    int i;
    for (i = pos; i < n - 1; i++)
        arr[i] = arr[i + 1];
 
    return n - 1;
}
 
// Function to implement search operation
int findElement(int arr[], int n, int key)
{
    int i;
    for (i = 0; i < n; i++)
        if (arr[i] == key)
            return i;
 
    return - 1;
}
 
// Driver code
int main()
{
    int i;
    int arr[] = {10, 50, 30, 40, 20};
 
    int n = sizeof(arr) / sizeof(arr[0]);
    int key = 30;
 
    printf("Array before deletion\n");
    for (i = 0; i < n; i++)
      printf("%d  ", arr[i]);
 
    n = deleteElement(arr, n, key);
 
    printf("\nArray after deletion\n");
    for (i = 0; i < n; i++)
      printf("%d  ", arr[i]);
 
    return 0;
}

Java

// Java program to implement delete
// operation in an unsorted array
  
class Main
{
    // function to search a key to
    // be deleted
    static int findElement(int arr[], int n, int key)
    {
        int i;
        for (i = 0; i < n; i++)
            if (arr[i] == key)
                return i;
      
        return -1;
    }
     
    // Function to delete an element
    static int deleteElement(int arr[], int n, int key)
    {
        // Find position of element to be
        // deleted
        int pos = findElement(arr, n, key);
      
        if (pos == -1)
        {
            System.out.println("Element not found");
            return n;
        }
      
        // Deleting element
        int i;
        for (i = pos; i< n - 1; i++)
            arr[i] = arr[i + 1];
      
        return n - 1;
    }
      
    // Driver Code
    public static void main(String args[])
    {
        int i;
        int arr[] = {10, 50, 30, 40, 20};
      
        int n = arr.length;
        int key = 30;
      
        System.out.println("Array before deletion");
        for (i=0; i

Python

# Python program to delete an element
# from an unsorted array
 
# Declaring array and key to delete
arr = [10, 50, 30, 40, 20]
key = 30
  
print("Array before deletion:")
print arr
  
# deletes key if found in the array
# otherwise shows error not in list
arr.remove(key)
print("Array after deletion")
print(arr)
  
# This code is contributed by Aditi Sharma.

C＃

// C# program to implement delete
// operation in an unsorted array
using System;
 
class main
{
    // Function to search a 
    // key to be deleted
    static int findElement(int []arr,
                           int n,
                           int key)
    {
         
        int i;
        for (i = 0; i < n; i++)
            if (arr[i] == key)
                return i;
     
        return -1;
    }
     
    // Function to delete an element
    static int deleteElement(int []arr,
                             int n,
                             int key)
    {
        // Find position of element
        // to be deleted
        int pos = findElement(arr, n, key);
     
        if (pos == - 1)
        {
            Console.WriteLine("Element not found");
            return n;
        }
     
        // Deleting element
        int i;
        for (i = pos; i < n - 1; i++)
            arr[i] = arr[i + 1];
     
        return n - 1;
    }
     
    // Driver Code
    public static void Main()
    {
        int i;
        int []arr = {10, 50, 30, 40, 20};
     
        int n = arr.Length;
        int key = 30;
     
        Console.Write("Array before deletion ");
        for (i = 0; i < n; i++)
        Console.Write(arr[i] + " ");
        Console.WriteLine();
     
        n = deleteElement(arr, n, key);
     
        Console.Write("Array after deletion ");
        for (i = 0; i < n; i++)
        Console.Write(arr[i]+" ");
    }
}
 
// This code is contributed by vt_m.

输出：

Array before deletion
10 50 30 40 20 

Array after deletion
10 50 40 20 

时间复杂度：
搜索： O(n)
插入： O(1)
删除： O(n)