"We pride ourselves on being fast. Chinese startups are faster."

"Work-life balance is nonexistent in Chinese startups.

Meetings are anytime — really. My meeting in Beijing with Hugo Barra, who runs all international expansion for Xiaomi — the cool smartphone maker and highest-valued startup in China, at around $45 billion or so — was scheduled for 11 pm, but got delayed because of other meetings, so it started at midnight. (Hugo had a flight to catch at 6:30 am after that.)

In China, there is a company work culture at startups that's called 9/9/6. It means that regular work hours for most employees are from 9 am to 9 pm, six days a week. If you thought Silicon Valley has intense work hours, think again.

For founders and top executives, it's often 9/11/6.5. That's probably not very efficient and useful (who's good as a leader when they're always tired and don't know their kids?) but totally common.

Teams get locked up in hotels for weeks before a product launch, where they only work, sleep and work out, to drive 100 percent focus without distractions and make the launch date. And while I don't think long hours are any measure of productivity, I was amazed by the enormous hunger and drive."

From https://www.recode.net/2016/5/13/11592570/china-startup-tech-economy-silicon-valley

A Number Theory Appetizer

Fix $x, y \in N$ such that $x$ and $y$ are coprime. Prove that there exists $n \in N$ such that $k | x^n - y^n$ for any $k \in N$.

A C puzzle

Consider the following C code:

#include <stdio.h>

enum bitmask
{
    bitmask_A = 1,
    bitmask_B = 2,
    bitmask_C = 4
};
typedef enum bitmask bitmask;

struct a_s
{
    bitmask member;
};
typedef struct a_s a_t;

bitmask
f(a_t *arg)
{
    arg->member |= bitmask_B;
    return bitmask_C;
}

int
main()
{
    a_t foo;
    foo.member = bitmask_A;
    foo.member |= f(&foo);
    printf("%d\n", foo.member);
    return 0;
}

What happens?

A Silly Physics Problem

Brought to you by Tyler Christensen

If you have two ideal 1F capacitors, one at 0V and one at 10V, and you connect them together instantaneously with an ideal superconductor, what is the final voltage? Note all components have zero physical size and there is zero parasitic inductance.