2526 - Find Consecutive Integers from a Data Stream.

Medium

For a stream of integers, implement a data structure that checks if the last k integers parsed in the stream are equal to value.

Implement the DataStream class:

• DataStream(int value, int k) Initializes the object with an empty integer stream and the two integers value and k.

• boolean consec(int num) Adds num to the stream of integers. Returns true if the last k integers are equal to value, and false otherwise. If there are less than k integers, the condition does not hold true, so returns false.

Example 1:

Input "DataStream", "consec", "consec", "consec", "consec"

[4, 3, 4, 4, 4, 3]

Output: null, false, false, true, false

Explanation:

DataStream dataStream = new DataStream(4, 3); //value = 4, k = 3
dataStream.consec(4); // Only 1 integer is parsed, so returns False.
dataStream.consec(4); // Only 2 integers are parsed.
                      // Since 2 is less than k, returns False.
dataStream.consec(4); // The 3 integers parsed are all equal to value, so returns True.
dataStream.consec(3); // The last k integers parsed in the stream are [4,4,3].
                      // Since 3 is not equal to value, it returns False.

Constraints:

• <code>1 <= value, num <= 10⁹</code>

• <code>1 <= k <= 10⁵</code>

• At most <code>10⁵</code> calls will be made to consec.