Binary TreesBinary Trees36

  1. 1Preorder Traversal of a Binary Tree using Recursion
  2. 2Preorder Traversal of a Binary Tree using Iteration
  3. 3Postorder Traversal of a Binary Tree Using Recursion
  4. 4Postorder Traversal of a Binary Tree using Iteration
  5. 5Level Order Traversal of a Binary Tree using Recursion
  6. 6Level Order Traversal of a Binary Tree using Iteration
  7. 7Reverse Level Order Traversal of a Binary Tree using Iteration
  8. 8Reverse Level Order Traversal of a Binary Tree using Recursion
  9. 9Find Height of a Binary Tree
  10. 10Find Diameter of a Binary Tree
  11. 11Find Mirror of a Binary Tree - Todo
  12. 12Inorder Traversal of a Binary Tree using Recursion
  13. 13Inorder Traversal of a Binary Tree using Iteration
  14. 14Left View of a Binary Tree
  15. 15Right View of a Binary Tree
  16. 16Top View of a Binary Tree
  17. 17Bottom View of a Binary Tree
  18. 18Zigzag Traversal of a Binary Tree
  19. 19Check if a Binary Tree is Balanced
  20. 20Diagonal Traversal of a Binary Tree
  21. 21Boundary Traversal of a Binary Tree
  22. 22Construct a Binary Tree from a String with Bracket Representation
  23. 23Convert a Binary Tree into a Doubly Linked List
  24. 24Convert a Binary Tree into a Sum Tree
  25. 25Find Minimum Swaps Required to Convert a Binary Tree into a BST
  26. 26Check if a Binary Tree is a Sum Tree
  27. 27Check if All Leaf Nodes are at the Same Level in a Binary Tree
  28. 28Lowest Common Ancestor (LCA) in a Binary Tree
  29. 29Solve the Tree Isomorphism Problem
  30. 30Check if a Binary Tree Contains Duplicate Subtrees of Size 2 or More
  31. 31Check if Two Binary Trees are Mirror Images
  32. 32Calculate the Sum of Nodes on the Longest Path from Root to Leaf in a Binary Tree
  33. 33Print All Paths in a Binary Tree with a Given Sum
  34. 34Find the Distance Between Two Nodes in a Binary Tree
  35. 35Find the kth Ancestor of a Node in a Binary Tree
  36. 36Find All Duplicate Subtrees in a Binary Tree

Find Maximum and Minimum in Array using Loop - Algorithm and Examples



Problem Statement

Given an array of integers, your task is to find the maximum and minimum values present in the array using a simple loop (without any built-in functions).

If the array is empty, there is no maximum or minimum, and the result should indicate that appropriately (e.g., null or a message).

Examples

Input ArrayMaximumMinimumDescription
[10, 20, 5, 8, 30]305Normal case with unordered elements
[5, 5, 5, 5]55All elements are equal
[-10, -5, -3, -20]-3-20All elements are negative
[100]100100Only one element in the array
[]nullnullEmpty array — no max or min can be determined

Solution

To find the maximum and minimum values in an array, we can simply scan through the array one element at a time and keep track of the largest and smallest values we encounter.

When the Array Has Elements

We start by assuming the first element is both the maximum and the minimum. Then, we go through the rest of the array and compare each value:

  • If the current value is larger than our current maximum, we update the maximum.
  • If the current value is smaller than our current minimum, we update the minimum.

This way, by the time we reach the end of the array, we will have found the true maximum and minimum values.

When the Array Has One Element

If the array has just a single element, then that element is both the maximum and the minimum, since there's nothing else to compare it to.

When All Elements Are Equal

If every number in the array is the same, then that number is both the maximum and minimum. For example, in [7, 7, 7], the answer is max = 7, min = 7.

When the Array is Empty

If the array is empty, we can't find either maximum or minimum values. There's simply no data to evaluate. In such cases, we should either return null, an empty result, or show a message like "No elements to compare"—depending on how we want to handle such edge cases.

Conclusion

This approach is very intuitive and works efficiently for arrays of any size. It's also helpful in understanding how scanning and comparing work in a loop, making it an excellent beginner problem.

Visualization

Algorithm Steps

  1. Given an array of numbers arr.
  2. Initialize max_val and min_val with the first element of the array.
  3. Iterate through each element in the array starting from the second element.
  4. If the current element is greater than max_val, update max_val.
  5. If the current element is less than min_val, update min_val.
  6. After the loop, return max_val and min_val.

Code

Python
Java
JavaScript
C
C++
C#
Kotlin
Swift
Go
Php
def find_max_min_loop(arr):
    max_val = arr[0]
    min_val = arr[0]
    for num in arr[1:]:
        if num > max_val:
            max_val = num
        if num < min_val:
            min_val = num
    return max_val, min_val

# Sample Input
arr2 = [-5, -1, -9, 0, 3, 7]
max_val, min_val = find_max_min_loop(arr2)
print("Maximum:", max_val)
print("Minimum:", min_val)

Time Complexity

CaseTime ComplexityExplanation
Best CaseO(n)Even in the best case, every element must be checked to ensure no smaller or larger values exist.
Average CaseO(n)Each element is visited once to compare and possibly update the maximum or minimum.
Average CaseO(n)In the worst case, the loop still traverses the entire array to determine the max and min values.

Space Complexity

O(1)

Explanation: Only a fixed number of variables (e.g., max_val, min_val) are used, regardless of input size.

Detailed Step by Step Example

Let us take the following array and apply the logic to find the maximum and minimum elements.

{ "array": [6,3,8,2,7,4], "showIndices": true, "specialIndices": [] }
{ "array": [0,6,6], "showIndices": false, "emptyIndices": [1, 2], "emptyCompIndices": [0], "labels": { "1": "max", "2": "min" } }

Initialize max = 6 and min = 6 with the first element of the array.

Check index 1

Compare 3 at index=1 with current max = 6 and min = 6.

3 is smaller than current min. Update min = 3.

{ "array": [6,3,8,2,7,4], "showIndices": true, "highlightIndices": [1], "specialIndices": [], "labels": {"1":"i"} }
{ "array": [0,6,3], "showIndices": false, "emptyIndices": [1, 2], "emptyCompIndices": [0], "labels": { "1": "max", "2": "min" } }

Check index 2

Compare 8 at index=2 with current max = 6 and min = 3.

8 is greater than current max. Update max = 8.

{ "array": [6,3,8,2,7,4], "showIndices": true, "highlightIndices": [2], "specialIndices": [], "labels": {"2":"i"} }
{ "array": [0,8,3], "showIndices": false, "emptyIndices": [1, 2], "emptyCompIndices": [0], "labels": { "1": "max", "2": "min" } }

Check index 3

Compare 2 at index=3 with current max = 8 and min = 3.

2 is smaller than current min. Update min = 2.

{ "array": [6,3,8,2,7,4], "showIndices": true, "highlightIndices": [3], "specialIndices": [], "labels": {"3":"i"} }
{ "array": [0,8,2], "showIndices": false, "emptyIndices": [1, 2], "emptyCompIndices": [0], "labels": { "1": "max", "2": "min" } }

Check index 4

Compare 7 at index=4 with current max = 8 and min = 2.

No update required.

{ "array": [6,3,8,2,7,4], "showIndices": true, "highlightIndices": [4], "specialIndices": [], "labels": {"4":"i"} }
{ "array": [0,8,2], "showIndices": false, "emptyIndices": [1, 2], "emptyCompIndices": [0], "labels": { "1": "max", "2": "min" } }

Check index 5

Compare 4 at index=5 with current max = 8 and min = 2.

No update required.

{ "array": [6,3,8,2,7,4], "showIndices": true, "highlightIndices": [5], "specialIndices": [], "labels": {"5":"i"} }
{ "array": [0,8,2], "showIndices": false, "emptyIndices": [1, 2], "emptyCompIndices": [0], "labels": { "1": "max", "2": "min" } }

Final Result:

Maximum = 8, Minimum = 2

{ "array": [6,3,8,2,7,4], "showIndices": true, "labels": { "2": "max", "3": "min" }, "specialIndices": [] }
{ "array": [0,8,2], "showIndices": false, "emptyIndices": [1, 2], "emptyCompIndices": [0], "labels": { "1": "max", "2": "min" } }


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