Little Algorithm help

Question

I have a functions that runs some pass/fail code and I want to keep track of the most recent 100 results.
void function passFailFunction() {
  int total = 0;
  int passes = 0;
  // This is some condition, but for this lets leave it as infinite loop...
  while (true) {
    if (getTrueOrFalse()) {
      passes++;
    total++;
    System.out.println("Pct: " + passes/total * 100);
}I want to modify this so it only keeps the percent for the 100 most recent iterations of the loop and disregard the other passes. Performance is absolutely key to what I need.
What would be a good way to tackle this with minimal performance hit.
For example if the first 50 iterations are passes and the next 50 are fails I have a pass % of 50%.
Now if the next 25 iterations are all fails I would want to be showing 0% pass not 25% pass.

Answer 1

avalanche333 wrote:
What would be a good way to tackle this with minimal performance hit.Use a circular buffer array. You will also need to tinker with your pass-count as you overwrite values.
For example if the first 50 iterations are passes and the next 50 are fails I have a pass % of 50%.
Now if the next 25 iterations are all fails I would want to be showing 0% pass not 25% pass.Why? You're only throwing out the first 25 tests, that still leaves 25/100 tests passing in your last 100 iterations.
Edited by: DeltaGeek on Apr 28, 2009 4:21 PM