c++ 二分法查找（binary_search）

#include <iostream>     // cout
#include <algorithm>    // binary_search, sort
#include <vector>       // vector
using namespace std;
bool myfunction (int i,int j) { return (i<j); }

int main () {
    int myints[] = {,,,,,,,,};
    vector<int> v(myints,myints+);                         // 1 2 3 4 5 4 3 2 1

    // using default comparison:
    sort (v.begin(), v.end());

    cout << "looking for a 3... ";
    if (binary_search (v.begin(), v.end(), ))
        cout << "found!\n"; else cout << "not found.\n";

    // using myfunction as comp:
    sort (v.begin(), v.end(), myfunction);

    cout << "looking for a 6... ";
    if (binary_search (v.begin(), v.end(), , myfunction))
        cout << "found!\n"; else cout << "not found.\n";

    return ;
}