upper bound lower bound implementation code example

Example: lower bound upper bound cpp

// lower_bound/upper_bound example
#include      // std::cout
#include     // std::lower_bound, std::upper_bound, std::sort
#include        // std::vector

int main () {
  int myints[] = {10,20,30,30,20,10,10,20};
  std::vector v(myints,myints+8);           // 10 20 30 30 20 10 10 20

  std::sort (v.begin(), v.end());                // 10 10 10 20 20 20 30 30

  std::vector::iterator low,up;
  low=std::lower_bound (v.begin(), v.end(), 20); //          ^
  up= std::upper_bound (v.begin(), v.end(), 20); //                   ^

  std::cout << "lower_bound at position " << (low- v.begin()) << '\n';
  std::cout << "upper_bound at position " << (up - v.begin()) << '\n';

  return 0;
}