wfe2017's blog

Strange Memory Limit Exceeded Error
By wfe2017, history, 8 years ago, In English

I was looking at my previous codes and I noticed a very strange Memory Limit Exceeded Error. The error occurred on test case 24, which has 127 numbers in the array, while in all previous test cases, I used at most 4MB. Does anyone have an explanation? The only large chunk of memory I allotted in my code is a 200,000-longlongint array which shouldn't take more than 2MB. However, in this test case, I used 256MB and got MLE.

http://codeforces.net/contest/615/submission/19726073

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8 years ago, # |
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8 years ago, # |
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While calculating numberoffactor, you haven't considered modulo 1e9 + 7 operation.
So as it overflows the size of long long, it will become negative and your ipow function will keep on calling itself forever, hence the memory limit error because of stack size overflow. I added a line in your ipow function to avoid such case and its not giving memory limit exceeded. Obviously its nor giving AC, but WA.

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