int*a;int*b=&a;a=&b; for 20 in C (or replace int with void to get rid of the warnings for 22 :P) 
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Consider an n by n binary matrix. If it has rank r <= n, then we want to compute the largest number bits flips necessary to reduce its rank to a specific value. All computations should be done over \$\mathbb{F}_2\$ (that is mod 2).
If r = n, then the answer is 1 to change it to n-1. If r = 1, it...
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The recent design update to the profile page removed the ability to easily navigate to a user's network profile, even though they chose to hide their profile. Since that functionality is not always used for benign purposes, I wrote a userscript to bring it bac...
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Half derivative of a polynomial (WIP)
In this challenge you will write a function \$f : \mathbb Q[x] \rightarrow \mathbb Q[x]\$ which takes and gives a rational polynomial, such that \$f^2\$ is the ordinary derivative with respect to \$x\$.
You may implement any function so long as it satisfies t...
Add numbers from 1 to n and devide the result by n+1 (Unfinished)
This whole challenge came from this math problem that my brain made;
(1+2+3+4+5+6+7+8+9+10)/11
And if this is copied from somewhere that I failed like for the fifth time already
