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what is a good way to select a random element from a map? C++. It is my understanding that maps don't have random access iterators. The key is a long long and the map is sparsely populated.
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Yes, std::map models AssociativeContainer just as you expect. Are you trying to ask why map is not called a "random access data structure"? That's just because we call it an AssociativeContainer, but the meaning is similar.
C++ map find() function is used to find an element with the given key value k. If it finds the element then it returns an iterator pointing to the element. Otherwise, it returns an iterator pointing to the end of the map, i.e., map::end().
One way to generate these numbers in C++ is to use the function rand(). Rand is defined as: #include <cstdlib> int rand(); The rand function takes no arguments and returns an integer that is a pseudo-random number between 0 and RAND_MAX.
map<...> MyMap; iterator item = MyMap.begin(); std::advance( item, random_0_to_n(MyMap.size()) ); If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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