CODEWITHSUNDEEP
cprintf
sherrellbc
sherrellbc

Reputation: 4853

What does this result from printf indicate?

I periodically get extraneous results when I run a program I have constructed. Instead of printing a float, I get this: -1.#IO. What does this result indicate? A divide by zero?

In my experience, if the result was an overflow then it should still print correctly, just a an incorrect value (perhaps some large negative).

Here is what I am getting most of the time:

enter image description here

Here is what happens about every 6-7 runs.

enter image description here

If I run the program using a constant seed (assuming that seed produces correct results), then everything works fine indefinitely. However, if I run using a random seed, like time(0), I tend to see this program explode at run-time.

In short, has anyone experienced this result before? Just looking for a starting point to dive into the code.

Upvotes: 0

Views: 426

Answers (1)

Criticize SE actions means ban
Criticize SE actions means ban

Reputation: 58858

On Windows, infinity is printed as 1.#INF. A quirk in the standard library means that rounding it to three decimal places gives 1.#IO ('F' >= '5', so it increments the 'N').

For the same reason, -1.#IO is negative infinity.

And yes, you could get this result by dividing by zero.

Upvotes: 3

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