Menu
I want to check if a vector of integers has any duplicates or not, and have to return true if it does. So I try to do something like this:
vector<int> uGuess = {1,2,3,3,4,5}
vector<int> a = uGuess;
sort(a.begin(), a.end());
bool d = unique(a.begin(), a.end());
And this will not work since unqiue cannot be assigned as a bool value. How should I proceed towards this? If I were to write a for loop to perform the same action, how should I do that?
793
Generic function to find duplicates in vector :Create a Generic function to get the duplicate elements and their duplication count i.e. * Generic function to find duplicates elements in vector. for (auto it = countMap. begin() ; it !=
Yes, but sorting a vector modifies the original content.
The unique() function in C++ helps remove all the consecutive duplicate elements from the array or vector. This function cannot resize the vector after removing the duplicates, so we will need to resize our vector once the duplicates are removed. This function is available in the <algorithm.
Proof (a) Suppose that 0 and 0 are both zero vectors in V . Then x + 0 = x and x + 0 = x, for all x ∈ V . Therefore, 0 = 0 + 0, as 0 is a zero vector, = 0 + 0 , by commutativity, = 0, as 0 is a zero vector. Hence, 0 = 0 , showing that the zero vector is unique.
The algorithm you're looking for is std::adjacent_find.
// The container must be sorted!
const std::vector<int> sortedVector = {1,2,3,3,4,5};
const bool hasDuplicates = std::adjacent_find(sortedVector.begin(), sortedVector.end()) != sortedVector.end();
Unlike std::unique, std::adjacent_find doesn't modify the container.
As a bonus, std::adjacent_find returns an iterator to the first element in the duplicate "pair":
const auto duplicate = std::adjacent_find(sortedVector.begin(), sortedVector.end());
if (duplicate != sortedVector.end())
std::cout << "Duplicate element = " << *duplicate << "\n";
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
