dating many women same time - C validating a credit card

This situation seems to call for an inject_with_index(), and look what doug meyer wrote: I guess he felt the same way, though I would have added this method to Enumerable instead of Array.Others used a hand rolled map_with_index() in similar ways.In fact, if you subtract nine from any double over ten you will get the same sum.

c validating a credit card-86

It's an easy enough process, but I found myself using an odd combination of Regexp and eval() when I was fiddling with it: I knew that was ugly and wanted to see how you guys would pretty it up. I had to print that Array inside of the inject() call during each iteration to see how it built up the answer.

I do want to show you a slew of interesting tidbits though.

Sum all doubled and untouched digits in the number3.

If that total is a multiple of 10, the number is valid For example, given the card number 4408 0412 3456 7893: Step 1: 8 4 0 8 0 4 2 2 6 4 10 6 14 8 18 3Step 2: 8 4 0 8 0 4 2 2 6 4 1 0 6 1 4 8 1 8 3 = 70Step 3: 70 % 10 == 0 Thus that card is valid.

Now, if you want to get away from all this index checking, you need to take a more functional approach and some solutions definitely did that.

Here's the same algorithm we've been examining from Ryan Leavengood's code: This process is interesting, I think, so let's walk through it.The interesting part is that N is chosen from the arity of your provided block.If we ask for two at a time, we get two; ask for three and we get three: That's a pretty smart iterator, I say. Work has been rough this week and I need some down time.Now Ryan chose to build up the digits and then sum, but you could do both in the same iterator.The first number is only ever one digit, so it's only the second number that needs special handling: Ryan's version is probably still a little cleaner though.This passes the digits into inject() two at a time, so the block can just double the second one.

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