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Reverse an array.

Certification: Basic Level Accuracy: 70% Submissions: 10 Points: 10

Write a C++ program that reverses a given array in place.

Example 1
    
  
  • Input: array = [1, 2, 3, 4, 5]
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  • Output: [5, 4, 3, 2, 1]
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  • Explanation:
    
      
      
    • Step 1: Initialize two pointers, one at the beginning and one at the end of the array.
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    • Step 2: Swap the elements pointed by the two pointers.
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    • Step 3: Move the left pointer one step right and the right pointer one step left.
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    • Step 4: Repeat until the pointers meet or cross each other.
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    •
Example 2
    
  
  • Input: array = [10, 20, 30, 40]
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  • Output: [40, 30, 20, 10]
    • 
  
  • Explanation:
    
      
      
    • Step 1: Initialize two pointers, one at the beginning and one at the end of the array.
      • 
      
    • Step 2: Swap the elements pointed by the two pointers.
      • 
      
    • Step 3: Move the left pointer one step right and the right pointer one step left.
      • 
      
    • Step 4: Repeat until the pointers meet or cross each other.
      • 
    
    
  
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Constraints
    
  
  • 1 ≤ len(array) ≤ 10^6
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  • -10^9 ≤ array[i] ≤ 10^9
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  • Time Complexity: O(n), where n is the length of the array
    • 
  
  • Space Complexity: O(1)
    •
ArraysControl StructuresTutorialspointGoldman Sachs
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Hint
Solution

Solution Hints

    
  
  • Use two pointers, one at the start and one at the end of the array.
    • 
  
  • Swap the elements at the two pointers and move the pointers towards the center.
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  • Stop when the pointers meet or cross each other.
    •

Steps to solve by this approach:

 Step 1: Define a function reverseArray that takes a vector of integers by reference.
 Step 2: Initialize two pointers - one at the start and one at the end of the array.
 Step 3: While the start pointer is less than the end pointer, swap the elements they point to.
 Step 4: Increment the start pointer and decrement the end pointer after each swap.
 Step 5: In main, create a vector with values and call reverseArray.
 Step 6: Loop through the reversed array and print the elements.

Submitted Code :