c++ STL binary_search() demo

// from c++ essential

#include <iostream>#include <vector>#include <algorithm>using namespace std;int main(){int arr[] = {1, 2, 99, 34, 26};size_t array_size = sizeof(arr) / sizeof(*arr);vector<int> ivec(arr, arr + array_size);sort(ivec.begin(), ivec.end());int target = 999;bool result = binary_search(ivec.begin(), ivec.end(), target);cout << target << " " << (result ? "" : "not ") << "exists." << endl;return 0;}