Never seen before C++ for loop

Question

I was converting a C++ algorithm to C#. I came across this for loop:

for (u = b.size(), v = b.back(); u--; v = p[v]) 
b[u] = v;

It gives no

Answer 1

This will be the C# form of your loop.

// back fetches the last element of vector in c++.
for (u = b.size(), v = b.back(); (u--) != 0; v = p[v]) 
{      
  b[u] = v;      
}

Just replace equivalent for size() and back().

What it does is reverses the list and stores in an array. But in C# we directly have system defined function for this. So you don't need to write this loop also.

b = b.Reverse().ToArray();