c++ - Kick out duplicate entries across vectors -

i have vectors , retrieve 1 vector contains entries aren't duplicated anywhere in input vectors.

#include <vector> int main() {    std::vector<int> = {2, 1, 3};   std::vector<int> b = {99, 1, 3, 5, 4};   std::vector<int> c = {5, 6, 7, 1};    // magic retrieve {2, 99, 4, 6, 7} (order doesn't matter)  } 

is there library function can performing task efficiently?

i'm not tied using vectors. solution include lists, sets, or whatever appropriate task.

using unordered_map, o(n) space complexity , o(n) time complexity:

#include <vector> #include <unordered_map> #include <iostream>  std::vector<int> get_unique_values(std::initializer_list<std::vector<int>> vectors) {   std::unordered_map<int, size_t> tmp;   auto insert_value_in_tmp = [&tmp](int v) {     auto = tmp.find(v);     if (i == tmp.end())       tmp[v] = 1;     else if (i->second != 2)       i->second = 2;   };    ( auto& vec : vectors) {     ( auto vec_value : vec ) {       insert_value_in_tmp(vec_value);     }   }    std::vector<int> result;   (auto v : tmp) {     if (v.second == 1)       result.push_back(v.first);   }    return result; };  int main() {    std::vector<int> = {2, 1, 3};   std::vector<int> b = {99, 3, 5, 4};   std::vector<int> c = {5, 6, 7};    std::vector<int> result = get_unique_values({a,b,c});    (auto v : result) {     std::cout << v << " ";   }   std::cout << '\n';    return 0; }