Find Second Smallest in Array

Algorithm Steps

Given an array of numbers arr.
Initialize min_val and second_min to Infinity.
Iterate through each element in the array.
If the current element is less than min_val, update second_min to min_val, and then update min_val.
Else if the current element is less than second_min and not equal to min_val, update second_min.
After the loop, return second_min.

Find Second Smallest using Loop - Optimal Approach Code

Python

JavaScript

Java

C++

def find_second_smallest(arr):
    min_val = float('inf')
    second_min = float('inf')
    for num in arr:
        if num < min_val:
            second_min = min_val
            min_val = num
        elif num < second_min and num != min_val:
            second_min = num
    return second_min

# Sample Input
arr = [30, 20, 10, 50, 60, 40]
print("Second Smallest:", find_second_smallest(arr))

Detailed Step by Step Example

Let's find the second smallest number in the array using a loop.

{ "array": [30,20,10,50,60,40], "showIndices": true }

Initialize min = Infinity and secondMin = Infinity.

Check index 0

Current element is 30. Compare with min = Infinity and secondMin = Infinity.

30 is smaller than current min. Update: secondMin = Infinity, min = 30.

{ "array": [30,20,10,50,60,40], "showIndices": true, "highlightIndices": [0], "labels": {"0":"i"} }

{ "array": ["",30,null], "showIndices": false, "emptyIndices": [1, 2], "emptyCompIndices": [0], "labels": { "1": "min", "2": "secondMin" } }

Check index 1

Current element is 20. Compare with min = 30 and secondMin = Infinity.

20 is smaller than current min. Update: secondMin = 30, min = 20.

{ "array": [30,20,10,50,60,40], "showIndices": true, "highlightIndices": [1], "labels": {"1":"i"} }

{ "array": ["",20,30], "showIndices": false, "emptyIndices": [1, 2], "emptyCompIndices": [0], "labels": { "1": "min", "2": "secondMin" } }