# You are given a 0-indexed integer array nums. # The concatenation of two numbers is the number formed by concatenating their numerals. # For example, the concatenation of 15, 49 is 1549. # The ...

So, you want to get better at those tricky LeetCode Python problems, huh? It’s a common goal, especially if you’re aiming for tech jobs. Many people try to just grind through tons of problems, but ...

One idle evening last October, Mehtaab Sawhney took up an old pastime. He began perusing the website erdosproblems.com, an updated record of the 1,179 conjectures left behind by the eccentric and ...

What are the most pressing global crises in 2026? Each year, the International Rescue Committee’s (IRC) Emergency Watchlist identifies the countries at greatest risk of new or worsening humanitarian ...

Five years ago, mathematicians Dawei Chen and Quentin Gendron were trying to untangle a difficult area of algebraic geometry involving differentials, elements of calculus used to measure distance ...

Microsoft’s MSFT-0.46%decrease; red down pointing triangle Copilot chatbot has become central to its artificial-intelligence strategy as the company’s close partnership with OpenAI diminishes. But the ...

Amateur mathematicians are using artificial intelligence chatbots to solve long-standing problems, in a move that has taken professionals by surprise. While the problems in question aren’t the most ...

Neutral-atom arrays are a rapidly emerging platform to create quantum computers. In a foundational study led by graduate students Aaron Holman and Yuan Xu from the Will and Yu labs, respectively, the ...

Getting good at LeetCode Java can feel like a puzzle sometimes, right? You see all these problems, and you’re not sure where to even start. This guide is here to break down the common approaches and ...

We look into the mental health crisis affecting American youth. By Sam Sifton I am the host of The Morning. The numbers are staggering. Nearly one in four 17-year-old boys in the United States has ...

Java-first solutions with concise, readable implementations. Per-problem folder: solution source + Solution.md notes. Small helper script and a template to scaffold new problems quickly. From the ...

You probably don’t need more time. By Jancee Dunn When I look back on all the major decisions I’ve dithered over, I could scream. It took me a decade to commit to becoming a parent. I wavered for a ...