Data Structure Array: Longest Monotonically Increasing Subsequence Size

http://www.geeksforgeeks.org/longest-monotonically-increasing-subsequence-size-n-log-n/

 #include <iostream>
 #include <vector>
 #include <algorithm>
 #include <queue>
 #include <stack>
 #include <string>
 #include <fstream>
 #include <map>
 using namespace std;

 int maxsum(int arr[], int n) {
     vector<int> tail;
     tail.push_back(arr[]);
     for (int i = ; i < n; i++) {
         if (arr[i] < tail[]) tail[] = arr[];
         else if (arr[i] > tail[tail.size()-]) tail.push_back(arr[i]);
         else {
             int mid;
             int left = ;
             int right = tail.size() - ;
             while (left < right) {
                 mid = (left + right) / ;
                 if (tail[mid] < arr[i]) left = mid + ;
                 else right = mid - ;
             }
             mid = (left + right) / ;
             tail[mid] = arr[i];
             cout << "tail[" << mid << "] is arr[" << i << "] = " << arr[i] << endl;
         }
     }
     return tail.size();
 }

 int main() {
     int arr[] = {, , , , , , , , };
     cout << maxsum(arr, ) << endl;
     return ;
 }