distinctksubarray.cpp

#include <iostream>
#include <initializer_list>
#include<bits/stdc++.h>

using namespace std;

vector<int> longestDistinctKSubarray(vector<int> nums, int k) {
    vector<int> ret;
    if (k == 0)
        return ret;
        
    unordered_map<int, int> table;
    int lAns = 0, rAns = 0;
    for (int i=0, uniqueCount=0, left=0; i<nums.size(); i++) {
        table[nums[i]]++;
        if (table[nums[left]] == 1) {
            uniqueCount++;
        }
        while (uniqueCount > k) {
            if (--table[nums[left++]] == 0) {
                uniqueCount--;
            }
        }
        if (i - left > rAns - lAns) {
            lAns = left;
            rAns = i;
        }
    }
    return {nums.begin() + lAns, nums.begin() + rAns};
}

int main() {
    for (int x: longestDistinctKSubarray({1,1,1,2,3},2)) cout << x << " ";
}

// 1 2 3
// 1