dictionary - How does one test item membership in an unordered sequence (C++)? -

i've used python long time, , i'm beginning use c++

in python, if 1 has set or dictionary relatively easy boolean value indicating whether or not particular item in sequence using in keyword. i.e.

a = set(2,4,3)    if 4 in   print "yes, 4 in a, thank asking!" 

it's more efficient doing this:

a = [2,3,4]   number in >if number == 4   >>return "yes, 4 in a, thank asking!" 

is there way make membership test simple , efficient in cpp or have iterate through ordered sequence?

you have functionality in std::set , tr1::unordered_set (not yet in c++ standard).

#include <set> #include <cstdio>  int main() {      std::set<int> s;      s.insert(1);              s.insert(2);      s.insert(4);      if (s.find(4) != s.end())           puts("4 found!");      return 0; } 

in reality, if data set small, linear search may still faster option.