Package g2101_2200.s2145_count_the_hidden_sequences

Class Solution

java.lang.Object
g2101_2200.s2145_count_the_hidden_sequences.Solution
public class Solution extends java.lang.Object
2145 - Count the Hidden Sequences.

Medium

You are given a 0-indexed array of n integers differences, which describes the differences between each pair of consecutive integers of a hidden sequence of length (n + 1). More formally, call the hidden sequence hidden, then we have that differences[i] = hidden[i + 1] - hidden[i].

You are further given two integers lower and upper that describe the inclusive range of values [lower, upper] that the hidden sequence can contain.

  • For example, given differences = [1, -3, 4], lower = 1, upper = 6, the hidden sequence is a sequence of length 4 whose elements are in between 1 and 6 ( inclusive ).
    • [3, 4, 1, 5] and [4, 5, 2, 6] are possible hidden sequences.
    • [5, 6, 3, 7] is not possible since it contains an element greater than 6.
    • [1, 2, 3, 4] is not possible since the differences are not correct.

Return the number of possible hidden sequences there are. If there are no possible sequences, return 0.

Example 1:

Input: differences = [1,-3,4], lower = 1, upper = 6

Output: 2

Explanation: The possible hidden sequences are:

  • [3, 4, 1, 5]

  • [4, 5, 2, 6]

Thus, we return 2.

Example 2:

Input: differences = [3,-4,5,1,-2], lower = -4, upper = 5

Output: 4

Explanation: The possible hidden sequences are:

  • [-3, 0, -4, 1, 2, 0]

  • [-2, 1, -3, 2, 3, 1]

  • [-1, 2, -2, 3, 4, 2]

  • [0, 3, -1, 4, 5, 3]

Thus, we return 4.

Example 3:

Input: differences = [4,-7,2], lower = 3, upper = 6

Output: 0

Explanation: There are no possible hidden sequences. Thus, we return 0.

Constraints:

  • n == differences.length
  • 1 <= n <= 105
  • -105 <= differences[i] <= 105
  • -105 <= lower <= upper <= 105

  • Constructor Summary

    Constructors
    Constructor
    Description
    Solution()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    numberOfArrays(int[] diff, int lower, int upper)
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • numberOfArrays

      public int numberOfArrays(int[] diff, int lower, int upper)