longest increasing subsequence nlogn code example

Example: longest increasing subsequence techie delight

#include <iostream>
#include <vector>
using namespace std;
 
// Iterative function to find longest increasing subsequence
// of given array
void findLIS(int arr[], int n)
{
    // LIS[i] stores the longest increasing subsequence of subarray
    // arr[0..i] that ends with arr[i]
    vector<int> LIS[n];
 
    // LIS[0] denotes longest increasing subsequence ending with arr[0]
    LIS[0].push_back(arr[0]);
 
    // start from second element in the array
    for (int i = 1; i < n; i++)
    {
        // do for each element in subarray arr[0..i-1]
        for (int j = 0; j < i; j++)
        {
            // find longest increasing subsequence that ends with arr[j]
            // where arr[j] is less than the current element arr[i]
 
            if (arr[j] < arr[i] && LIS[j].size() > LIS[i].size())
                LIS[i] = LIS[j];
        }
 
        // include arr[i] in LIS[i]
        LIS[i].push_back(arr[i]);
    }
 
    // uncomment below lines to print contents of vector LIS
    /* for (int i = 0; i < n; i++)
    {
        cout << "LIS[" << i << "] - ";
        for (int j : LIS[i])
            cout << j << " ";
        cout << endl;
    } */
 
    // j will contain index of LIS
    int j;
    for (int i = 0; i < n; i++)
        if (LIS[j].size() < LIS[i].size())
            j = i;
 
    // print LIS
    for (int i : LIS[j])
        cout << i << " ";
}
 
int main()
{
    int arr[] = { 0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11, 7, 15 };
    int n = sizeof(arr)/sizeof(arr[0]);
 
    findLIS(arr, n);
 
    return 0;
}