Minimize operations to make all array elements -1 by changing maximums of K-size subarray to -1

 <script>
        // JavaScript Program to implement
        // the above approach

        // Function to find minimum the number
        // of operations required to make all
        // the array elements to -1
        function minOperations(arr, N, K) 
        {

            // Stores the array elements with
            // their corresponding indices
            let vp = [];
            for (let i = 0; i < N; i++)
            {

                // Push the array element
                // and it's index
                vp.push({ "first": arr[i], "second": i });
            }

            // Sort the elements according
            // to it's first value
            vp.sort(function (a, b) { return a.first - b.first; });

            // Stores the minimum number of
            // operations required
            let minCnt = 0;

            // Traverse until vp is not empty
            while (vp.length > 0) {
                let val, ind;

                // Stores the first value of vp
                val = vp[vp.length - 1].first;

                // Stores the second value of vp
                ind = vp[vp.length - 1].second;

                // Update the minCnt
                minCnt++;

                // Pop the back element from the
                // vp until the first value is
                // same as val and difference
                // between indices is less than K
                while (vp.length > 0
                    && (vp[vp.length - 1].first == val)
                    && (ind - vp[vp.length - 1].second + 1 <= K)) {
                    vp.pop();
                }
            }

            // Return the minCnt
            return minCnt;
        }

        // Driver Code
        let arr = [18, 11, 18, 11, 18];
        let K = 3;
        let N = arr.length;

        document.write(minOperations(arr, N, K));

     // This code is contributed by Potta Lokesh
    </script>