14, 7, 22Max 22
Find Biggest of Three Numbers in Python
What you’ll learn
- How to find the largest of three numbers using a clear if-elif-else ladder.
- How the same result can be written with max(a, b, c) or nested max style.
- How tie cases (equal values) behave, and how to explain complexity in interviews.
Overview
Given a, b, and c, return the value that is not smaller than the other two. If two or three values tie for largest, returning any one of those tied largest values is valid.
Quick examples
5, 5, 3Max 5
-1, -4, -2Max -1
Live preview
Enter three numbers and check the biggest value instantly.
Algorithm
Check a
If a >= b and a >= c, return a.
Else check b
If b >= a and b >= c, return b.
Otherwise return c
If first two checks fail, c is biggest.
📜 Pseudocode
Pseudocode
function find_biggest(a, b, c):
if a >= b and a >= c:
return a
if b >= a and b >= c:
return b
return c1
If-elif-else approach
python
def find_biggest(num1: int, num2: int, num3: int) -> int:
if num1 >= num2 and num1 >= num3:
return num1
elif num2 >= num1 and num2 >= num3:
return num2
return num3
number1 = 14
number2 = 7
number3 = 22
result = find_biggest(number1, number2, number3)
print(f"The biggest number is: {result}")2
Built-in max() approach
python
def find_biggest_with_max(a: int, b: int, c: int) -> int:
return max(a, b, c)
a, b, c = 14, 7, 22
print(f"The biggest number is: {find_biggest_with_max(a, b, c)}")❓ FAQ
You compare the values using if-elif conditions, or use max(a, b, c). Both return the largest value.
Using >= handles ties clearly. If two numbers are equal and largest, one valid maximum is still returned correctly.
Yes. You can directly use max(a, b, c). In interviews, writing the if-elif version first helps show your logic.
For exactly three numbers, time complexity is O(1) and extra space is O(1).
Yes. Comparisons work the same way for negative values too.
Use a loop with a running maximum, or max() on a list/array of values.
Edge cases and pitfalls
Ties
Equal largest values
For input like 5, 5, 3, the answer is still 5.
Negatives
All values negative
The greatest value is the least negative number.
Input type
Int vs float
The same idea works for floats too; just change type hints if needed.
⏱️ Time and space complexity
| Approach | Time | Extra space |
|---|---|---|
| If-elif checks for 3 numbers | O(1) | O(1) |
Built-in max(a, b, c) | O(1) | O(1) |
Summary
- Goal: find the largest of 3 values.
- Methods: if-elif-else comparisons or
max(). - Complexity: constant time and constant extra space.
Did you know?
To find the biggest of 3 values, you only need a few comparisons, so the solution runs in O(1) time and O(1) space.
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