find_the_second_smallest_number_in_an_array.md

Find the Second Smallest Number in an Array

Find the Second Smallest Number in an Array

To find the second smallest number in an array, iterate through the array while keeping track of the smallest and second smallest values.

Algorithm:

1. Initialize two variables to store the smallest and second smallest values, starting with Infinity.
2. Iterate through the array and update the smallest and second smallest values as you go.
3. Return the second smallest number.

Example:

function findSecondSmallest(arr) {
    let smallest = Infinity;
    let secondSmallest = Infinity;

    for (const num of arr) {
        if (num < smallest) {
            secondSmallest = smallest;
            smallest = num;
        } else if (num < secondSmallest && num > smallest) {
            secondSmallest = num;
        }
    }

    return secondSmallest === Infinity ? null : secondSmallest;
}

// Example usage
console.log(findSecondSmallest([5, 3, 8, 1, 6])); // Output: 3
console.log(findSecondSmallest([1, 1, 1])); // Output: null

This method has a time complexity of O(n), where n is the length of the array.

Tags: intermediate, JavaScript, Arrays, Algorithm