23 lines
617 B
Markdown
23 lines
617 B
Markdown
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Let's look ate the diagonal numbers of our 5x5 grid:
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|n |info |
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|--|---------------|
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|25|starting number|
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|21| = 25 - **4** |
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|17| = 21 - **4** |
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|13| = 17 - **4** |
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|9 | = 13 - **4** |
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|7 | = 9 - **2** |
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|5 | = 7 - **2** |
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|3 | = 5 - **2** |
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|1 | = 3 - **2** |
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You can probably see the pattern here. The rest of the algorithm is simply loop from 1001^2 to 1, subtracting the right amount each round and in the end summing up all numbers.
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I have this little code to calculate the sum of stack values until a zero is encountered:
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```befunge
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>+\:#<_$
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```
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Perhaps it's useful for someone else.
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