Unique visitors

  • Estimate
  • Flow 13

Difficulty 3 of 5

Count 100 million distinct visitors. An exact set uses 24 bytes each. A HyperLogLog with 1,024 six-bit registers has about 3.25 percent error; error falls with the square root of the register count. Use a power-of-two count for at most 1 percent error. Size the array in KiB.

Play level

The question

Answer with one number in KiB.

Each worker adds one network cardDrag or use arrow keys to change the workers

Goals and limits

p99 latency
under 200 ms
Monthly cost
under 10 USD/mo
Traffic
100 req/s

Concepts

How players did

Player results load from the server.

All levels