unordered-map

C++ unordered_map using a custom class type as the key

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I am trying to use a custom class as key for an unordered_map, like the following: #include <iostream> #include <algorithm> #include <unordered_map> using namespace std; class node; class Solution; class Node { public: int a; int b; int c; Node(){} Node(vector<int> v) { sort(v.begin(), v.end()); a = v[0]; b = v[1]; c = v[2]; } … Read more

Is there any advantage of using map over unordered_map in case of trivial keys?

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A recent talk about unordered_map in C++ made me realize that I should use unordered_map for most cases where I used map before, because of the efficiency of lookup ( amortized O(1) vs. O(log n) ). Most times I use a map, I use either int or std::string as the key type; hence, I’ve got … Read more