HLD solution for Promotion Counting(Platinum) #4886
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| segtrees[i] = segTree((int)heavy_paths[i].size()); | ||
| } | ||
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| sort(cow_proficiency.begin(), cow_proficiency.end(), greater<pair<int, int>>()); |
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sort(cow_proficiency.begin(), cow_proficiency.end(), greater()) also works btw
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it works locally but throws a compile error on usaco
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most guide code is written to be submitted in C++ 17 I'm pretty sure
cuz like, with C++ there's literally no disadvantage with going with a higher version (I'm pretty sure)
if ur curious why, it's cuz of class template argument deduction
| Add Centroid Decomp/HLD Solution | ||
| **Time Complexity:** $\mathcal{O}(N\log ^2N)$ | ||
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| Sort the nodes from largest to smallest value, do path updates from each node to the root. |
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i get what you mean but like, maybe make the wording a bit more specific
like: "Sort the nodes in descending order of proficiency. When adding in each node, we do a path update from the root to this node." (except be specific with what type of path update we do)
| #include <bits/stdc++.h> | ||
| using namespace std; | ||
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| template <class T> class SumSegmentTree { |
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put this in a codesnip
| } | ||
| }; | ||
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| void dfs_hld(vector<vector<int>> &edges, vector<vector<int>> &heavy_paths, |
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ok i personally find this to be kind of ugly, ngl
IMO there's two ways to clean it up
- make these global arrays (sans might make u change it tho lol)
- lambda dfs
I would say don't change it yet, but be aware that you might be asked to later.
| depth[i] = depth[start] + 1; | ||
| dfs_hld(edges, heavy_paths, depth, sizes, i); | ||
| sizes[start] += sizes[i]; | ||
| if (heavy_child == -1 || sizes[heavy_child] < sizes[i]) heavy_child = i; |
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just in general put braces around blocks of code even if it's one statement
| int main() { | ||
| freopen("promote.in", "r", stdin); | ||
| freopen("promote.out", "w", stdout); | ||
| int N, current_value; |
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very, very, very minor but preferably use n instead of N
| } | ||
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| sort(cow_proficiency.begin(), cow_proficiency.end(), greater<pair<int, int>>()); | ||
| for (auto &p : cow_proficiency) { |
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consider using a structured binding
e.g. for (auto &[thing_a, thing_b] : cow_proficiency) or something
| if (heavy_index[p.second] != -1) { | ||
| ans[p.second] = | ||
| segtrees[heavy_index[p.second]].range_sum(0, path_index[p.second] + 1); | ||
| } else ans[p.second] = cur_ans[p.second]; |
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