DEV Community: Irina

Leetcode 118. Pascal's Triangle

Irina — Sat, 16 Sep 2023 03:12:27 +0000

Hello Dev Community,
I'm posting my solution to the Leetcode problem #118. Pascal's Triangle Easy

Description:

Given an integer numRows, return the first numRows of Pascal's triangle.

In Pascal's triangle, each number is the sum of the two numbers directly above it as shown:

var generate = function(numRows) {
    let res = []

    for (let i = 0; i < numRows; i++) {
        let arr = new Array(i+1)
        arr[0] = arr[arr.length - 1] = 1

        for (let j = 1; j < arr.length-1; j++) {
            arr[j] = res[i-1][j-1] + res[i-1][j]
        }

        res.push(arr)
    }

    return res
};

console.log(generate(5));
[[1],[1,1],[1,2,1],[1,3,3,1],[1,4,6,4,1]]

Method - Nested loops
Complexity - Time O(n^2) | Space O(n^2). Basically complexity here is the product of height and width of the triangle i * j, which simplifies to n^2.

I welcome your comments or suggestions!

Leetcode #1299 - Replace Elements with Greatest Element on Right Side

Irina — Thu, 14 Sep 2023 19:43:11 +0000

Hello Dev Community,
I'm posting my solution to the Leetcode problem #1299 - Replace Elements with Greatest Element on Right Side Easy

Problem description:

Given an array arr, replace every element in that array with the greatest element among the elements to its right, and replace the last element with -1.
After doing so, return the array.

var replaceElements = function (arr) {
    let res = new Array(arr.length);
    let max = 0;
    res[arr.length - 1] = -1;

    for (let i = arr.length - 1; i > 0; i--) {
        max = Math.max(arr[i], max);
        res[i - 1] = max;
    }

    return res;
};

console.log(replaceElements([17, 18, 5, 4, 6, 1])); 
// [ 18, 6, 6, 6, 1, -1 ]

Method - Two pointers (i and i-1)
Complexity - Time O(n) | Space O(n)

Leetcode stats:
Runtime - beats 78.21%
Memory - beats 60.18%

I welcome your comments or suggestions!

Adding social share tags to your website

Irina — Fri, 13 Nov 2020 08:46:38 +0000

If we want to share our website on social media such as Twitter, FB or LinkedIn, we may need to ensure our site is shareable and has a preview image, title and description.

In order to do so, we need to include special metatags into our HTML head. Tags that have twitter: keyword are required for Twitter cards, and tags with og: keyword are for Facebook and LinkedIn cards.

Here's an example of tags I added for a website I just finished and wanted to share on social.

    <meta name="twitter:card" content="summary" />
    <meta name="twitter:site" content="@irinakramer" />
    <meta name="twitter:title" content="Evaluate News with NLP" />
    <meta name="twitter:description"
        content="Check an article for sentiment such as positivity, subjectivity and irony. Powered by MeaningCloud API." />
    <meta name="twitter:image" content="https://evaluate-news-nlp-17.netlify.app/evaluate-news-screenshot.png" />
    <meta property="og:title" content="Evaluate News with NLP" />
    <meta property="og:description"
        content="Check an article for sentiment such as positivity, subjectivity and irony. Powered by MeaningCloud API." />
    <meta property="og:type" content="website" />
    <meta property="og:url" content="https://evaluate-news-nlp-17.netlify.app/" />
    <meta property="og:image" content="https://evaluate-news-nlp-17.netlify.app/evaluate-news-screenshot.png" />

This is how this tweet appears in my feed:

Just to make sure our tags work correctly, we can validate them on Twitter and Facebook developer sites:
https://cards-dev.twitter.com/validator
https://developers.facebook.com/tools/debug/

There are more options for these tags and details can be found here:
https://developer.twitter.com/en/docs/twitter-for-websites/cards/overview/markup
https://ogp.me/

PS: This was my first ever blog post, so please forgive if something isn't perfect. Feedback is appreciated!