Tree from nesting levels: Difference between revisions
Added C++ implementation
(→{{header|Perl}}: Added iterative solution) |
(Added C++ implementation) |
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Line 120:
return recursion's recurse(input, 1)
end treeFromNestingLevels</lang>
=={{header|C++}}==
Uses C++20
<lang cpp>#include <any>
#include <iostream>
#include <iterator>
#include <vector>
using namespace std;
// Make a tree that is a vector of either values or other trees
vector<any> MakeTree(input_iterator auto first, input_iterator auto last, int depth = 1)
{
vector<any> tree;
while (first < last && depth <= *first)
{
if(*first == depth)
{
// add a single value
tree.push_back(*first);
++first;
}
else // (depth < *b)
{
// add a subtree
tree.push_back(MakeTree(first, last, depth + 1));
first = find(first + 1, last, depth);
}
}
return tree;
}
// Print an input vector or tree
void PrintTree(input_iterator auto first, input_iterator auto last)
{
cout << "[";
for(auto it = first; it != last; ++it)
{
if(it != first) cout << ", ";
if constexpr (is_integral_v<remove_reference_t<decltype(*first)>>)
{
// for printing the input vector
cout << *it;
}
else
{
// for printing the tree
if(it->type() == typeid(unsigned int))
{
// a single value
cout << any_cast<unsigned int>(*it);
}
else
{
// a subtree
const auto& subTree = any_cast<vector<any>>(*it);
PrintTree(subTree.begin(), subTree.end());
}
}
}
cout << "]";
}
int main(void)
{
auto execises = vector<vector<unsigned int>> {
{},
{1, 2, 4},
{3, 1, 3, 1},
{1, 2, 3, 1},
{3, 2, 1, 3},
{3, 3, 3, 1, 1, 3, 3, 3}
};
for(const auto& e : execises)
{
auto tree = MakeTree(e.begin(), e.end());
PrintTree(e.begin(), e.end());
cout << " Nests to:\n";
PrintTree(tree.begin(), tree.end());
cout << "\n\n";
}
}
</lang>
{{out}}
<pre>
[] Nests to:
[]
[1, 2, 4] Nests to:
[1, [2, [[4]]]]
[3, 1, 3, 1] Nests to:
[[[3]], 1, [[3]], 1]
[1, 2, 3, 1] Nests to:
[1, [2, [3]], 1]
[3, 2, 1, 3] Nests to:
[[[3], 2], 1, [[3]]]
[3, 3, 3, 1, 1, 3, 3, 3] Nests to:
[[[3, 3, 3]], 1, 1, [[3, 3, 3]]]
</pre>
=={{header|Go}}==
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